In case someone finds this helpful. There is a way to do 2 of 3 or 2 of 4 monitors with RDP, however, it requires another piece of software. Unfortunately this is the only way I've found to do this...
Requires: VMware Workstation
1. Create a Windows 7 workstation. No frills no other software (except maybe anti-virus).
(Note: I run it with only 2gig and 1 processor... never tried 1 gig)
2. Turn it on, and set to full-screen
3. Set it to use the Monitors you want to use for RDP
4. Run your RDP Session in the workstation.
It works out great. I realize that this isn't REALLY a fix, and if you don't already have VMWare, it's a bit of an expense to purchase JUST for this purpose. But if you have it already, it works really well.
Greg