Oh then NTFS, just making sure you weren't using FAT32. And this problem is confirmed to be a corrupt file, or just assumed since reinstalling is the only fix you have found? Then yes they should probably add a file checker. a checker of files. a program that scans each files MD5 hash, and reinstalls the file/s with incorrect MD5s. The reason even very old MMO's did this is its very easy to program to check, and they even have the file distribution in place. My guess why they haven't: ????