I've just come across a new Mozilla / Firefox extension that may help troubled users.
It is called ListZilla, and it will essentially make an HTML code listing of all the installed themes, chromes and extensions that are installed into your profile so that others may help debug your problem(s).
http://roachfiend.com/archives/2005/03/03/listzilla/
InfoLister is another one:
http://mozilla.doslash.org/infolister/
I have not yet tried either of these as I don't have the time right now, but could someone let us know how well these extensions perform and perhaps what level of information they output?
Cheers.