i get this error quite often:
this.docShell has no properties
actually, i don't know if it's because of PatternSkin
in 4.0.2, but that's my guess at this point.
I don't have a clue. I can't find anything with "docShell" in the TWiki directory.
has quite a few hits on this message, sounds like some extension to ff could be playing tricks on you?
Discarding pending more details.