I know this is an old thread, but this is exactly what my unit is doing now. It freezes and sometimes restarts and works then freezes again or just freezes and then restarts and freezes etc.
I have checked my VIN and there are no updates available for my 2009 Dodge Journey SXT. This is beyond frustrating especially because it works then doesn't etc. Our vehicle has the Infinity sound system and from what I have read it is a pain in the butt to put in an aftermarket system; I believe it was something that the aftermarket decks can't power the infinity speakers or something like that.