Jim specifically mentioned that the "drive serial number" (Identifier String?) was corrupted. If the rest of the log was OK (no corruption of the log text) then it's likely that one or more data bits on the databus to the IDE drive is being corrupted. Sources of this could either be a databus buffer going bad, a bad cable, or a dodgy solder joint on the header (yes, I know!). Again, start off with the cheapest option - a correctly dimensioned IDE cable, properly installed.