I'm using Kubuntu, 64bit, and have been using Beryl.

When I have Beryl effects on, and I do a ctrl+alt+shift+f1, and then go back with an alt-f7, I get a black screen with the mouse pointer. I can't get back to any runtime mode (or whatever it's called) with any more key combinations. It basically seems locked at this point, and I end up having to hit the hard reset button.

Can anything be done at that point, or do I just need to make sure I go back to a non-3d window manager before doing a ctrl+alt+shift+f1 so I'll be able to go back later?

What is ctrl+alt+shift+f1 suppose to do?

To get to the basic shell in a different runlevel--like if I wanted to have HTOP running in another level and wanted to switch to it, and then switch back to the desktop.

Try Ctrl+F7 to switch back to your desktop. I'm not sure if it's a requirement of Beryl that you use the shift key in order to switch to a shell, usually Alt+Ctrl+(F1-F6) does the job.