This is in org-mobile.el. I discovered this while learning to use MobileOrg.
The section of the code that writes out the Priorities (line 462 in org version 7.9.2) totally ignores the variables org-highest-priority and org-lowest-priority, and simply sets the #+ALLPRIORITIES value to "A B C". In my case, I have org-highest-priority set to '1', and org-lowest-priority set to '5', so I would expect #+ALLPRIORITIES to be set to "1 2 3 4 5". My elisp-fu is non-existant, so could someone please fix this to enable MobileOrg to work more correctly? Thank you all for your efforts on this great product. I use Org all the time, for years now. Dave in St. Petersburg, FL, USA