Comment 8 for bug 153995

I've just installed gutsy and have noticed the same problem. Fortunately, I discovered a decent workaround: start rdesktop at a resolution very slightly smaller then your full-screen resolution. For example, my laptop's resolution is 1280x800, so I start rdesktop like this:

rdesktop -g 1280x799 <hostname>

When rdesktop comes up, it will be in a window, and you will be able to easily switch between fullscreen and windowed mode using Ctrl-Alt-Enter. Of course, your RDP session won't use the bottom row of pixels on your screen, but that seems like a small price to pay. Also, you'll probably have to start rdesktop from the command line, as it doesn't seem that tsclient and grdesktop support passing arbitrary resolutions to rdesktop.