With the new system, I can't delete old queries; I have to go purge them from my cookie file manually....
I think that happens because Bugzilla now creates cookies with path /bugzilla/ instead of / and when it is asked to delete old queries, it deletes /bugzilla/ cookie, but does not delete the / cookie. It should probably delete both in order to be backwards compatible.
the query code has been re-written to not use cookies any longer. old queries should be saved correctly and all cookies removed.
I had to remove the old cookies manually. After that almost everything worked fine