Comment 22 for bug 36215

I'm on ppc (mac mini) running Breezy (latest updates), installed from Colony3 cd.
I had the exact same problem.
Deleting the file "~/.update-notifer/hooks_seen" as you said solved the problem.

You wanted the files in "~/.update-notifer"?
I only had 1 file in that folder. (hooks_seen)

If it is to any help, the content of that file was:

notification-2.6.12-6-powerpc 1124802716 0
notification-2.6.12-7-powerpc 1124470103 0