I have deployed a number of T400 laptops with XP pro sp3. They started blue-screening and spontaneously rebooting. The machines are in AHCI mode and I updated the intel matrix driver to version 22.214.171.1244 dated 11/3/2008. I also have some pc's running the latest and greatest version which has escaped my mind at the moment. The bsod and the shutdowns have ceased, but I still get the error in the event logs and I have at least one user that gets the error and then he loses his dvd drive after the error occurs. Sometimes it comes back sometimes it takes time. The iastor.sys errors are intermittent sometimes I only see them once a week. Is anyone else having this issue. I do not want to switch back to compatibility mode.