My computer's been fine recently. But I don't know if it's because I followed the instructions above, and delted all those com. files, or because I reinstalled a new version of iScrobble.
(edit: oops, sorry, I realise now that my problem was solved on the official mac support boards. I'll dig...
I've had exactly the same problem (but I'm a new mac user, and so don't really understand how to diagnose it)
I do have a bunch of prgrams as login items, but it would be difficult to test them, as this problem is unpredictable...