Ugh.
OK, one thing that will interest you - PG 7.0.3, a maintenance update,
is due to be released momentarily. A fair number of bugs will be
fixed in that release. I know there were at least one or two
involving VACUUM.
Your notion of doing an initdb and reloading from scratch is as good
as any for now. If it fails with PG 7.0.3 when that becomes available
you most certainly want to inform the PG folks. Tom Lane would
probably be absolutely thrilled to get a dump of the database that
kills VACUUM in this case...
