If I have a 1.5.0 rdesktop session to an XP (may be other OS's) computer and I am typing (in no particular application) AND at the same moment I am typing I receive a popup notification from outlook web access (may also occur with other popups, but these are my most common), then my rdesktop session locks. No further mouse or keyboard input is possible. The only fix is to terminate the session and start a new one.
This problem does NOT occur with 1.4.1. The problem is easily reproduced.
The session is from Linux (2.4.29 kernel).
If I am not typing at the moment the pop-up occurs the session does not lock.
My command line is usually this (for 1.5.0: I add -a 24 to 1.4.1):
rdesktop-1.5.0/rdesktop -x l -r sound:local -g 1590x1190 xpbox 2>/dev/null