I purchased less than one week ago a 1TB Buffalo External Hard Drive model HD-PA1-OTU3-AP MiniStation Thurderbolt. I had formatted for use on Mac and PCs. I then downloaded some 500 GB of data on the disk. I used it on my MAC (13 inch Mac Retina, operating on OSX 10.8.3 ) and it worked just fine for the first few times. I tried to use on my desktop PC but it failed to recognize the disk. The same day in the evening I used it once to see a movie on my Mac (which was wonderful). When I finished I ejected the disk by dragging it in the trash. The next day when I tried to use it again on the Mac I received the following message: The disk you inserted was not readable by this computer. Initialize Ignore Eject When I pressed initialize and then the verify option, I received the following messages: Verifying partition map for ST1000LM024 HN-M101MBB Media Checking prerequisites Checking the partition list Problems were found with the partition map which might prevent booting Error: Partition map check failed because no slices were found. Any ideas what happened to my drive and how I can fixe it and not loose the data on the disk?? Thanks for you advice!