HP ScanJet Installs But Won't Communicate (Windows 98)

ScanJet 3570c USB scanner installs OK on 600MHz Pentium, Windows98 SE, 128MB (HP Pavilion 8676C).
But, attempting to scan results in:

"Failure to communicate with scanner. Be sure that the scanner is on and properly connected [1215]."
or
"An error occurred communicating with the scanning device. Please ensure that the scanning device is connected properly and try again."

When I press a button on the front of the scanner (e.g. "Copy"), the computer does receive the signal, but then responds with one of the above error messages.

Software install process completes without error (that I can see).
I plug in the scanner only once the software is installed, as directed.
Same scanner / install CD works correctly with a Windows XP laptop.

stimon.exe is running.

Device Manager shows no conflicting devices; shows ScanJet as "This device is working properly"

Control Panel - Scanners and Cameras - "ScanJet" appears, Properties button brings up a dialog with a "Test Scanner or Camera" button - pressing button produces "Your scanner or camera successfully completed the diagnostic test"

Formerly had a Microtek scanner installed via parallel port - have uninstalled the scanner software, deleted entries in Registry (I think), deleted and re-Plug'nPlay installed parallel port, to no avail.

I spent considerable time trying the suggestions on the HP web site, as well as talking directly with HP support people. From that, I did download the latest 4-in-1 driver for the VIA chipset, as well as the "usb filter" program from viaarena.com. I then purchased a BusLink PCI USB card containing an NEC controller chip, and downloaded the latest drivers. Finally, I purchased a Belkin PCI USB card containing the OPTi controller chip - because, of all the controller chips, OPTi seemed to have the fewest reported problems. I also tried having the ScanJet be the only device plugged into either USB controller, to avoid power issues. *ALL* of these changes produced no difference in behavior :-(

I have also used HP's 10-step procedure: "HP Scanjet Scanner - Resolving USB Scanner Initialization and Related Communication Error Messages" multiple times to uninstall the ScanJet software, including deleting registry entries, re-install, no change.

I downloaded & flashed the latest BIOS.

I have deleted twain* and twunk* files from C:\WINDOWS (see list below), and allowed the installation to restore these.

Some observations (either red herrings or smoking guns ???):
1) Suspicious _pnpscan.log (see below), but I think, from the timestamp, that this occurs during the software install - *NOT* at the time of actually plugging in the USB cable to the scanner.
2) There seems to be two instances of "ACPI IRQ Holder for PCI IRQ Steering" on IRQ 9 ??
3) Microsoft System Information lists one of the Scanjet's drivers as hpqgends.tmp, File Size: Driver Not Installed ??

Any help would be greatly appreciated !

Craig

***********************************************************
Microsoft System Information - IRQs
***********************************************************
0      System timer
1      Standard 101/102-Key or Microsoft Natural Keyboard
2      Programmable interrupt controller
3      Communications Port (COM2)
4      Communications Port (COM1)
4      Communications Port (COM3)
5      Communications Port (COM4)
6      Standard Floppy Disk Controller
7      Printer Port (LPT1)
8      System CMOS/real time clock
9      OPTi 82C861 PCI to USB Open Host Controller
9      HP EN1207D-TX PCI 10/100 Fast Ethernet Adapter
9      VIA Tech 3038 PCI to USB Universal Host Controller
9      ACPI IRQ Holder for PCI IRQ Steering
9      ACPI IRQ Holder for PCI IRQ Steering
9      SCI IRQ used by ACPI bus
10      Conexant PCI Modem Enumerator
10      Master Riptide PCI Audio Device
10      ACPI IRQ Holder for PCI IRQ Steering
11      Linksys Phoneline 10M Network Card
11      NVIDIA Vanta (HP - English)
11      ACPI IRQ Holder for PCI IRQ Steering
12      (free)
13      Numeric data processor
14      Primary IDE controller (dual fifo)
14      VIA Bus Master PCI IDE Controller
15      Secondary IDE controller (dual fifo)
15      VIA Bus Master PCI IDE Controller

***********************************************************
Microsoft System Information - Components
***********************************************************
 HP Scanjet 3500c Series
    Image
    Registry Key:                               HKEY_LOCAL_MACHINE\enum\USB\VID_03F0&PID_2005\SCN31GT118T1P
    Alloc resources:                           None
    Forced resources:                        None
    Boot resources:                            None
    Filtered resources:                       None
    Basic resources:                          None
    Driver:                                          Image\0007
    Driver Date:                                   6-20-2003
    Driver:                                          hpqgends.tmp
                                                         File Size: Driver Not Installed
                                                         File Date: Driver Not Installed
    Driver:                                          usbscan.sys
                                                         File Size: 8944 (0x22F0)
                                                         File Date: 9/25/2001 2:34 PM
                                                         Company Name: Microsoft Corporation
                                                         File Version: 4.10.1998
    Driver:                                          hpgt35.dll
                                                         File Size: 450560 (0x6E000)
                                                         File Date: 4/22/2002 1:48 PM
                                                         Company Name: Hewlett-Packard
                                                         File Version: 1.0.2.148
    Driver:                                          hpsjvset.dll
                                                         File Size: 131072 (0x20000)
                                                         File Date: 4/17/2002 4:07 PM
                                                         Company Name: Hewlett-Packard
                                                         File Version: 2.8.4.142
    Driver:                                          hpgtpusd.dll
                                                         File Size: 225280 (0x37000)
                                                         File Date: 4/22/2002 1:45 PM
                                                         Company Name: Hewlett-Packard
                                                         File Version: 1.3.1.148
   
***********************************************************
Microsoft System Information
***********************************************************
Microsoft Windows 98 4.10.2222 A
Clean install using /T:C:\WININST0.400 /SrcDir=C:\WINDOWS\OPTIONS\CABS /IS /IW /IQ /ID /IV /IZ /II /NR /II /C  /U:xxxxxxxxxxxxxxxxx
IE 5 6.0.2800.1106
Uptime: 0:00:50:41
Normal mode
On "PAVILION" as "Craig"
Hewlett-Packard
GenuineIntel x86 Family 6 Model 8 Stepping 1
128MB RAM
76% system resources free
Custom swap file on drive C (9579MB free)
Available space on drive C: 9579MB of 34823MB (FAT32)

***********************************************************
C:\WINDOWS\TEMP\_pnpscan.log
***********************************************************
Log File started Fri Jun 20 16:35:05 2003

szDriverPath: "c:\Program Files\Hewlett-Packard\Digital Imaging\Migrate\"
szPnPINF: "hpqratpk.inf"
szPnPID: "USB\Vid_03f0&Pid_2205"
PnPScanner:  PnP Update Failed
PnPScanner:  Update ConfigFlags in PnP registry area failed

***********************************************************
Deleted from C:\WINDOWS
***********************************************************
TWAIN001 MTX             5  06-11-03 10:06p Twain001.Mtx
TWAIN    LOG           547  06-11-03 10:06p TWAIN.LOG
TWAIN    DLL        87,328  04-23-99 10:22p twain.dll
TWAIN_32 DLL        94,208  04-23-99 10:22p twain_32.dll
TWUNK_32 EXE        90,112  04-23-99 10:22p twunk_32.exe
TWUNK002 MTX             0  03-11-00  6:49p Twunk002.MTX
TWUNK_16 EXE        48,560  07-17-02  2:18a twunk_16.exe
TWUNK003 MTX             0  03-11-00  6:49p TWUNK003.MTXStart Free Trial