Microsoft WSUS remote client update problem

I want to be able to monitor the update status of remote systems (laptops, etc.) that 'occasionally' connect to our network.

We have a Workgroup network setup - not Active Directory - and use registry settings (see below) to direct locally connected clients to use the WSUS server.

Locally connected clients (directed to WSUS with intranet IP address) are reporting and updating as expected.

Remote clients (directed to WSUS via http://FQDN:8530) successfully report status and receive update information from WSUS server, but are unable to download updates from WSUS server.
Port number used is 8530 (which the firewall forwards to port 80).
These same systems will update succesfully from Microsoft update and/or I can manually install any update via MS update.
....The problem lies somewhere in the download of updates to the remote client (when downloading from WSUS server).

All of the tests to verify communication with WSUS server are successful and I have successfully run all of the recommended 'fixes' for the download error (0x80072efd).

Does anyone have any suggestions?

Thanks for any advice,

Terry McMillan
Secure Payment Systems



Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate]
"AcceptTrustedPublisherCerts"=dword:00000001
"TargetGroupEnabled"=dword:00000000
"TargetGroup"=""
"ElevateNonAdmins"=dword:00000000
"WUServer"="http://FQDN:8530"            
"WUStatusServer"="http://FQDN:8530"    

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU]
"AUOptions"=dword:00000004
"AUPowerManagement"=dword:00000001
"AutoInstallMinorUpdates"=dword:00000001
"DetectionFrequency"=dword:0000000a
"DetectionFrequencyEnabled"=dword:00000001
"IncludeRecommendedUpdates"=dword:00000001
"NoAUAsDefaultShutdownOption"=dword:00000001
"NoAUShutdownOption"=dword:00000001
"NoAutoRebootWithLoggedOnUsers"=dword:00000000
"NoAutoUpdate"=dword:00000000
"RebootRelaunchTimeout"=dword:0000000a
"RebootRelaunchTimeoutEnabled"=dword:00000001
"RescheduleWaitTime"=dword:0000000a
"RescheduleWaitTimeEnabled"=dword:00000001
"ScheduledInstallDay"=dword:00000000
"ScheduledInstallTime"=dword:00000003
"UseWUServer"=dword:00000001