This procedure fixed my problem on Mac OS X 10.9.1 with Arduino 1.0.5 and an OSEPP Uno R3 Plus
I was brand new to Arduino and was of course very disappointed when I could not get the simple Blink sketch to load.
I searched for quite a while before coming across this post and even then it was with the aid of a colleague
Since this is going to be a problem for anyone with a recent Mac OS it would have been nicer if there was a more prominent way of alerting Mac users.
Are Apple aware of the driver issue? Is it an actual problem with the Apple driver or a problem with the way Arduino 1.0.5 is trying to access the driver? I don't really like regressing the driver so it would be nice to know that someone, somewhere is working on a permanent fix for this... Do we need to post somewhere else to get Arduino development to take a closer look?
This is the sort of problem that one associates with Windows rather than the Mac!