Some things I've tried to fix the problem (without success)
Deleting all Mafia files
Removing and reinstalling Java
Using a Multi
Turning off Breakfast
Using new builds
I'm able to put an item in my display case, so it can access inventory (no, using gear changer on the menu tab doesn't work...
Also might be related - if I log out (using the weekly release) I have to quit the program and restart to log in again, otherwise it just tries several servers and then says "requests complete" and stops.