I was downloading some themes for my 8320 (I've had a BB before, but it's the 8100 and that was it), I got a couple to work BUT some didn't at all. I don't see them in the options list for the themes. So I remove them from the phone with the BB Manager and the themes are still in the app list when I view my apps in the manager.

I am using a Powerbook G4 mac laptop. I would like to know how to get them off for good! Also how come the other themes did show up (apparently they were installed fine). Thank you.

You need to be sure that the theme is compatible with your device model AND the OS version on the device.

Themes are device and OS specific as MM said above.