Here we go again. I just installed a third SATA drive in my Mac Pro, running Mountain Lion. The drive is a Seagate 500Mb Barracuda, and it was taken out of my Windows machine where it was a spare storage drive, working fine. I added it to my Mac Pro, as a third drive - two are storage and one is the startup. I had some trouble partitioning and formatting this drive as Mac Extended (Journaled) but I finally got it. Running Disk Utility reports no problems when verifying this drive. However, I cannot copy files from the other storage drive to the Seagate Barracuda: "The finder can't complete the operation because some data in "_________" can't be read or written. (Error code - 36). But, I can copy files from the first storage drive to my desktop, and I also tried copying to an external USB storage drive. So, it's not the files or the drive they're stored on, it seems to be the Seagate 500MB Barracuda. What to do? Give up on this Seagate drive? I've read some people have the same error message with a replacement drive, so...let's give this another shot. I'm not ready to give up on this drive, and I've tested it with TechTool. The Seagate is NOT formatted as FAT or any Windows format - it's formatted for a Mac. Delete the .DSstore files on the source drive? I've tried that after reading this as a cause of the problem. Same error message. Suggestions? Thanks.