There is probably some problem with Javascript. My NC4.61 shows: JavaScript Error: http://bugzilla.redhat.com/bugzilla/query.cgi, line 2590: f.product has no properties. JavaScript Error: http://bugzilla.redhat.com/bugzilla/query.cgi?Bugzilla_login=petr%40ryston. cz&Bugzilla_password=xxxxxx&GoAheadAndLogIn=1&GoAheadAndLogIn=Login, line 2589: f.product has no properties. BTW, I see that login name and password is sent in cleartext by GET request, it is the least safe way.
I am unable to duplicate this with the current version of bugzilla running on the machine. I may be missing something so if it still exists, please open a new bug.