i have a couple of computers with avast and when i updated one of them with windows 7 32 bit everything went ok until i rebooted the computer , the machine went into blue screen so i uninstalled and did a clean installed and the same thing happen with build 7.0.1474 with built 7.0.1473 i have had no problems at all so i had to reinstalled 7.0.1473 until it is fixed i dont want to put in the other machines until it is fix you guys can figure it out
there should be a memory dump or at least a minidump at windows directory. Could you upload it to ftp.avast.com/incoming ? It would help us to find the root cause of your problem.