disclaimer: i'm not exactly sure if this belongs in the software section or the hardware section so i'll start here. last night i decided to verify my hard drive in Disk Utility (for no other reason than curiosity). there was an issue (volume header needed repair, or something like that) and i fixed it by booting up from the DVD and repairing the hard disk through Disk Utility on the DVD. (i'm on a 15" CD MBP with 2GB RAM, OS X 10.4.8.) everything works great now. when i told my friend about it this morning, he decided to verify his disk (he's on a 15" 1.67 PB with 1.5GB RAM, OS X 10.4.8). when he verified it, his computer locked up and he was forced to do a hard reboot. when he tried it again, he had the same problem. any ideas what's causing his machine to lock up and any idea on how to fix it?