Firefox 1.0 on 98se - Download list stuck

A while ago I installed FF 1.0 on a friend's 98se computer.  Has been
working like a champ, except that lately the list of files in the
download manager window will not clear, and anytime he tries to
download something his machine will usually lock up.

Manually opening the download window and clicking on "clean up"
results either in absolutely nothing, or in FF locking up.

Is there a folder or file hiding somewhere that I could manually clean
out or delete that would accomplish the same thing?  It just seems
that this weirdness is contributing to some other general weirdness on
his computer.


Thanks.

Paul