Do a virex scan too. I do remember there was a virus or two that did this. Surprisingly enough for shits and giggles, with all the macs I have hauled home over the years at various states of dis-repair. I did do scans, and ended up with 3 different viruses between machines. its kinda funny. one of them was cdef virus, and another was NDIF i think. I cant remmeber the 3rd one.