[Orgmode] Problem sorting by priority

[Paul Mead]

Hi

I don't know how long this has been a problem, as I've only just started
using priorities on my tasks. 

I have a mixture of (usually) A and B priorities, and the rest have no
priority set. If I sort the list by priority, the A's sort to the
top as expected, but lower priorities stay where they are.

I've just done a check to see what happens with C priority items, and
the one I set up got sorted to below the `* Archive' heading!

Org-mode version 6.25b
GNU Emacs 22.3.1 (i386-mingw-nt6.0.6001) of 2008-09-06 on SOFT-MJASON
Windows Vista (yeah, I know)

This also happens on my other Windows machine, running `6.24trans' on
WinXP

Any ideas?
Paul