A bit late on the response, but in case future readers read this, I don't want them to have bad info.
Permissions Repair, sure. But I wouldn't do it, no. It uses BOMs for Leopard, which may or may not differ from that of Tiger. Who knows what odd behavior the Mac might exhibit after that?
Disk Repair, sure. It's not much more than a GUI'd fsck front end. No harm there.