i had the same problem and now it's completely gone, the fix: for some reason, i had to remove all my favorite contacts(so that the boxes are blank, don't delete the contacts). once they're removed, go into each contact(edit), then click on the notes section. if the notes page are filled with code, delete all the code, then you can re-enter them as favorites. this was a problem with the leo that htc put an update to fix on there website. it has something to do with syncing your contacts with active sync from sense 2.1 to sense 2.5. here's a link to a pocketnow article explaining the issue and fix
http://pocketnow.com/software-1/bug-...tact-favorites
no matter how unrelated this may sound to your issue, it might work. trust me, i had the "loading htc sense" frozen screen issue atleast twice a day and now it's been over 1 month without 1 problem