boot time scan initialize error

???Hi all, Every time I try to schedule a boot time scan and restart, avast boot time scan comes up with a error message that dissapears too quickly to get an error number. The scan is therefore cancelled and Windows begins to log on. I do know that part of the message said it was an initialize error. Can someone please help? I would really like to run a boot time scan as I havent for a few months now because of this.
Thanks in advance

read this post http://forum.avast.com/index.php?board=2;action=display;threadid=3675