Hi Guys,
I have the same problem with my MacBook Pro / official UNO.
I have tried to reset it, running a nightly version of the IDE, but no luck.
I am a bit stuck as I can't upload sketches using my Mac, and I cannot use the PC as it is running Windows XP, and it has the famous compiling error "ld returned 5 exit status"
So, I cant even start to have fun with my new toy 