Avast! 4 SBS Edition - errors in Antivirus event log every minute

We have a Windows 2003 SBS Server that is getting multiple errors in the Antivirus event log. We get 10 to 15 errors per minute. The error is:

VSAPI: Cannot scan object . Message was flagged as untestable. AAVM error code is 0x80046300.

How did you solve it?