Ok, this is going to sound really stupid. No matter what query I do, I cannot get b.m.o to return any bugs later than bug 231923. For example, if I choose the 'View Bugs Already Reported Today' link, it finishes at 231923. If I search for 'after' in 'MailNews' (Unconfirmed, New, Assigned, Reopened), I get bug 231923, but not bug 231924, both of which should match. I've also just commented on bug 231964, but I can't get it to come up on any search result. Am I going mad?
No, you are not going mad, but the problem is now fixed.