I've run into this issue a few times, and usually it just sorts itself out after a few days. Only it has become increasingly frustrating and I'm looking for a long time solution/answer. I'm currently using a MBPr on OS X 10.8.2 and a 1.5TB WD Portable Hardrive. The HD is partitioned in half to both NTFS and FAT32. I am trying to copy files over 200MB to the FAT32 partition, and it stops at 25MB and doesn't go any further. When trying to stop the transfer, that doesn't do anything either, and I have to forcibly remove the HD from my Mac. I have tried verifying and repairing the partition using Disk Utility, but that has done nothing as well. Any ideas and suggestions would be greatly appreciated!