My iMac has been shutting down on its own quite a bit lately. When I run the Disk Utility I get lots of msg's indicating a file has been modified and will not be repaired. Below is an example: Warning: SUID file "usr/bin/atrm has been modified and will not be repaired Anyone have any suggestions on how to resolve this? There are probably a dozen or more files with this problem. Is there a folder I can delete without causing any problems? Thanks everyone!!