Blank Screen after RDP logon

After logging in using RDP, I get a blank screen for a while and then
disconnect.

Once it looked like the desktop would load but only flashed on the screen
for a fraction of a second. I think I saw it say something like "hm sync
window error" but it was literally a flash on the screen.

VNC and LogMeIn both work fine, but I would prefer to use the RDP client only.

I have tried disabling the bitmap caching, different resolutions and color
depth, removing VNC, tried MTU 1300 and 1500, tried different user accounts,
and am out of ideas.

Thanks for your help.