I've just upgraded from 4.3.4 to 4.4, and I now find that in all issue lists, ordering by priorities (desc) goes in the order
- Major
- Critical
- Blocker
- Minor
- Trivial
I've checked the priority order is correctly sorted on the Issue Attributes / Priorities admin screen, and even tried moving them up and down to see if that would fix it. No dice -- this ordering seems to be fixed. Checking the "priority" table in the database shows that the sequence field has the correct ordering (as does the id), but interestingly, the natural order is as follows (sequence/id in brackets):
- (4) Minor
- (5) Trivial
- (1) Blocker
- (2) Critical
- (3) Major
It looks to me as though there's an ORDER BY clause that's missing... 
Any ideas on how to go about getting this rectified? Needless to say, it's extremely frustrating.