From the Stupid-Is-As-Stupid-Does Department:
There are still a couple VMWare-Server based machines on our network.
After installing the latest VMWARE-SERVER build under Ubuntu 9.10 I found that there was no way to send a CTRL-ALT-DEL! The good old CTRL-ALT-INSERT shortcut has absolutely no effect on Linux-Host, Windows-Guests, and there is no longer a menu option to send a CTRL-ALT-DEL. WOW!
Fear not folks, you can still get into those stubborn windows boxes. Use CTRL-ALT-PRNT SCRN. This will send a CTRL-ALT-DEL. Way to go VMWare!