Howto return to virtual machine when remote desktop hangs?

Question

I'm using a vmware virtual machine running ubuntu linux and from there I connect to a Windows XP machine using rdesktop through a VPN tunnel. This configuration is given and cannot be changed.

From time to time my internet connection does a reconnect. Then the running rdesktop (running in fullscreen mode) process freezes and isn't usable anymore. Now I want to return to the underlying linux and restart the rdesktop process. But I'm not able to get out of fullscreen rdesktop mode and so I cannot access the ubuntu desktop to kill any process.

My solution is to reboot the vmware and start the rdesktop again.

Is there a better way to get the configuration running again after a freeze?

EDIT:

I have no admin rights for the linux system. Everything must be done with user rights.

Answer 1

Turn on the X escape hatch:

$ gnome-keyboard-properties

and then Layouts ➤ Options... ➤ Key sequence to kill the X server ➤ enable.

http://superuser.com/questions/160620/unable-to-debug-reproduce-ubuntu-crash/160631#160631

Answer 2

Ctrl-Alt-Enter doesn't work?

How about switching to a different virtual console using Ctrl-Alt-F1, logging in, and killing your rdesktop process?

Or, ssh to your Ubuntu machine from your host OS and killing it that way?