OK, so I have been troubleshooting this issue with Microsoft for over a month now, and today, I finally figured out what is causing it, but how to permanently fix it. Here's the scenario:
I am running Windows Vista x86 with SP1 and all patches installed. My hardware consists of a Core 2 Duo CPU, and a GIG Intel NIC.
When I RDP to a Server, running Windows Server 2008, I will stay connected for about 10 seconds to 5 minutes, (It is random) and then get a error box saying, "Because of an error in data encryption, this session will end. Please try connecting to the remote computer again " I have also been getting this same error RDP'ing to a SBS 2003 server as well. I as well as Microsoft pointed the finger at the Firewall, in which I swapped that out and then the Firewall company (Sonicwall in this case) pointed to the ISP. The ISP on the other hand, looked at it and said, nope it's not us.
So after all of this finger pointing, I RDP'ed into the same Windows 2008 server from a XP workstation, with no SEP installed.... I stayed connected for hours, no problems. I came across this article
http://social.technet.microsoft.com/Forums/en-US/winserverTS/thread/3e4e9d8a-cf6a-4e7a-9072-f9ecd3f17a72 today indicating something to do with TCP Offloading, but in my case, it was not the fix.
What did fix it for me, until Symantec can tell me the permanent solution:
Start, Run, type in smc -stop (this stops SEP service on the client)
Now I RDP to the Windows 2008 server or Windows 2003 server, and no problem.
Is it the Teefer2 driver or something else?
Hopefully Symantec has an answer.
Lyle Epstein