Anyhow, I’m glad you found a solution and thanks for sharing it!

***UPDATE!***
Sorry for all the multiple posts, but I found a solution that works! It’s for any 32 or 64 bit versions from XP to Windows 7. I scanned it with the latest Nod32 signature and it’s clean.

http://deepxw.blogspot.com/2009/04/universal-termsrvdll-patch.html

I tried this again and I was wrong, it was not as simple as using the andrewblock.net hack to fix my problem. Let me go in to detail so I don’t give false hope to anyone else with this problem.
I use Total Uninstall v5. It takes a snapshot of your file system and registry, then you install something, then it takes another snapshot and compares the differences. When you want to uninstall something, it deletes all files that were created and resets all registry entries that were altered.
So here’s what I did step by step:
1. “uninstalled” the hack by reverting with Total Uninstall (this will not revert files that were changed, just deletes files that were added and reverts registry entries)
2. used a live XP PE disc called Hawk PE (any PE disc should do) to replace the original .dll that I had backed up (because I could not replace it while Vista was running… permission problem?)
3. restarted in to Vista, ran andrewblock.net hack

Only the 2nd time around did I realize it was not as simple as just running the andrewblock hack. I’m not sure why I can’t get this to work, but hopefully someone else can learn from my mistakes.
Also, I highly recommend Total Uninstall.

I backed up the .dll and registry settings, but I was not able to restore it to the previous 1-session RDP. I ran the x64 SP2 .bat from andrewblock.net. I’m not sure if that had an updated .dll or not, but it restored me back to 1-session RDP (still can’t do multiple).