I re-booted my pro yesterday, and got an error asking me if I would like to reformat this drive because it was unreadable by OSX. As usual I had other things to do and didn't get back to it for a while. When I opened Disk Utility I found it was a small FW drive I didn't use much. So no worries, but then I noticed the specs on the drive! If anyone wondered what size drive OSX could actually recognize, this should fill you in. Apple always gives maximums that we all prove not to be a limitation in time, but this was not expected!