Tech and Zyndstoff. Thanks for replies. In my first post "5000 High Risk items detected..." I detailed the sequence of events, to summarise I ran a Boot Time Scan just after receiving the dodgy VTS and after manualy deleting (not move to chest) about 10 I opted for "delete all", a bit rash perhaps. After about 500 a file was encountered which couldn't be deleted, moved, repaired or skipped (this is what I meant by "fell over". In hindsight it was probably a lucky break! My only option was to escape to abort scanning entirely. I then booted to Vista and ran a full scan from there, 4500ish items detected but no action taken. After a full MBAM scan (40ish low risk items removed) and updating to Avast 6 (of course with a good VPS) the system was clean.
Concerned about the 500 original deletions I checked recycle bin and found to my surprise the 500 items all with deletion time and date consistent with when I ran the boot time scan.
Does escaping from a scan perhaps not allow avast to clear its deletions from the recycle bin?