Comment 23 for bug 217868

I believe that there is a genuine problem with rdesktop, but also with gnome.
I use CISCO vpn, that might be the cause of rdesktop crashing, however rdesktop not only crashes but locks the mouse and keyboard inputs, even when the focus is not on the rdesktop window. The system becomes completely frozen and the only "local solution" is to manually reset.

FYI, this is being looked at the following bug report:
https://bugs.launchpad.net/ubuntu/+source/rdesktop/+bug/81854