Can't load bundle

On my 10.4.11 partition, I only had the screensaver installed for my admin user. I manually removed the bundle from "~/Library/Screen Savers", but when I tried to install the 2.7 screensaver, I got the "Can't load bundle" again. I removed the bundle manually once more, and then I could install and use the old 2.0.
Then I restarted my Intel Mac Mini to use OSX 10.5.1. I had no breveCreatures there already, and installing and using 2.7 went without problem. I noticed, however, that the 2.7 creatures seemed to move much slowlier than the 2.0 ones. Is that due to the fancy new graphics in 2.7?

/Jon

I have the same problem: It says Error: Can't load bundle. I don't know what your talking about when you say screensaver bundle (Not too computer smart) do you mean the brevecreatures.saver? I am using a Mac OSX 10.3.9.

I'm having the same problem. If this helps diagnose, the console displays this message when I try to select breveCreatures as screen saver:

2008-12-09 11:11:04.933 System Preferences[22904] *** -[NSBundle load]: Error loading code /Users/user/Library/Screen Savers/breveCreatures.saver/Contents/MacOS/breveCreatures for bundle /Users/user/Library/Screen Savers/breveCreatures.saver, error code 4 (link edit error code 4, error number 0 (Library not loaded: /usr/lib/libexpat.1.dylib
  Referenced from: /Users/user/Library/Screen Savers/breveCreatures.saver/Contents/MacOS/breveCreatures
  Reason: image not found))
2008-12-09 11:11:04.933 System Preferences[22904] ScreenSaverModules: can't get principalClass for /Users/user/Library/Screen Savers/breveCreatures.saver

Is this supposed to be Leopard only? I didn't see that anywhere. Thanks!

(And, I've tried this several times after removing the bundle manually, both installing for a single user and systemwide.)