I've set my endpoint to perform weekly scans and checking the log today I've noticed the following:
****************** Sophos Anti-Virus Log - 25/04/2012 07:51:16 **************
20120419 200000 Scan 'Scanner Profile' started.
20120419 200701 Unknown error 0x80070057 decomposing "".
(2 items)
Other users reported this to the sophos community as well
Unfortunately I don't have any internal address/filename next to the decomposing statement as per URL above
According to Sophos AutoUpdate: Sophos AutoUpdate error codes
the error is : One or more arguments are invalid (not sure if this applies as it's different product version)
Thanks