Apple uses a variety of drives in their computers. The 80GB in my 1.25Ghz AluPB was a Hitachi (IBM) and was very quiet. The 80GB Fujitsu that my current 1.5Ghz isn't quite as quiet. Currently the smallest drive for the 12" Powerbook is 60GB, but Apple will still have 40GB drives available since they use them with the iBooks. You obviously have software to check the SMART status of the drive, but have you run a surface check to check for bad sectors and other drive errors? As much as you've been having serious problems that point to a failure with the drive, Apple will need to find a problem, probably through their own hardware test. If there is a failure, they will replace the drive, but it is hard to tell what size they'd put in. I'm guessing 60GB, since that is the current 12" hard drive. Also, when my 1.25Ghz was replaced by Apple, they gave me a 1.5Ghz, even though the request for a new computer went through before the speedbump was announced. Apple also often uses different part numbers for the same part (e.g. the iMac's SO-DIMM is exactly the same as some Powerbooks/iBooks) so that is what also leads me to believe they wouldn't give you the 40Gb for the iBook. It will be interesting to see what happens.