I have seen a post like this before, but there was no reply.
Login to w2k3 TS server: (Rdesktop 1.5)

Rdesktop N k en_us

Login is fine and keyboard OK.
When started a rdp session within the terminal server to another server the Caps Lock key has a problem in full screen mode only.

It randoms upper and lower case keys like: WwfF, etc
When selected another keymap, same problem, only with “k none”, the error disappears, but then no arrow keys.
The keyboard functions are always OK on the primary TS session.
Anybody dealt with this before?