I just bought a new Toshiba laptop and immediately ran into the same problem. Don't know if it will help you, but Toshiba just posted a patch on their support site, along with the following information:
Title: Microsoft QFE KB822624 for Windows XP on Satellite A40/A45 models
Version: KB822624XP
Size: 434,920 bytes
Posted: 02/12/04
Released Date: 02/06/04
Operating System: Windows XP
Description: This QFE fixes an issue where the computer intermittently hangs with a black screen, or the sound is lost after restart