After the proboards upgrade, they've noticed loads of little bugs that affect things from functioning properley. I've had it confirmed that one of them is with the preset avatars. You may of noticed that they don't work the majority of the time. All the bugs will be fixed by the proboards guys in due course.
CopyofCpt, I've uploaded you avatar to imageshack and replaced it with that in your profile so it should work ok now, but change it if you wish