I just built a new system based on a Gigabyte GA-7VM400M running XP Pro and I'm having similar problems with three completely different modems:
Pragmatic I56PSP-F30 (PCTel PCT789T-C1 Chip)
Pragmatic I56LVP-F00 (Agere 1646T00 Chip) Lucent Winmodem
Dynalink 1456VQH-R Int1 (Rockwell R6785-62 Chip)
Basically XP recognizes and installs them with no problem. I query them and they respond. I can even dial-up to my ISP and they seem to work great. I can surf and download without any problem.
But then the connection either stalls or disconnects after between a couple of minutes to 15 or 20 minutes. After that I can't get the modem to reconnect. It dials, I hear the handshake, then 30 seconds of silence, then verifying user name and password for 30 seconds plus, then "Cannot connect the phonebook entry. Error 756: The connection is already being dialed." then "Unable to establish a network connection."
Another modem would take more than a minute to disconnect or completely lock up the computer. I'd have to restart Windows before I could dial-up again. Then same problem,
Yes, I've tried updating drivers on all three but nothing seems to be able to give me one reliable modem.
I know it's possible, but what are the chance of having three bad modems?
I've tried the modems in differrent PCI slots.
I don't have any IRQ conflicts (currently on 18 by itself).
I've updated the system BIOS.
I booted into safe mode and there are several more items under Network Adapters:
Realtek RTL8139 Family PCI Fast Ethernet NIC - Packet Scheduler Miniport
Realtek RTL8139/810X Family PCI Fast Ethernet NIC
WAN Miniport (IP)
WAN Miniport (IP) - Packet Scheduler Miniport
WAN Miniport (L2TP)
WAN Miniport (PPPOE)
WAN Miniport (PPTP)
Are these all necessary.
Thanks for your help.