I must say the log didn't show anything suspicious, the files were scanned as usual...
Anyway, I got probably slightly confused by the references to "quick scan" in some posts (it's not always clear where "quick scan" is used to describe Quick/Standard/Thorough scan sensitivity inside Simple UI, and when it means Explorer Extension (= ashQuick.exe)).
First, regarding the double scanning:
- When Simple UI runs a Standard or Thorough scan, it performs a rootkit scan first (on specific areas - not the whole disk, as far as I know). So, it may seem that these areas are scanned twice, but it's a different type of scan
- There's additional initial disk access that "browses" all the selected areas somehow - to estimate the size and display the progress somehow - so it File Monitor log, it might seem that there another scan running - but it's as expected.
So, you are saying the all the scans (ashQuick.exe, boot-time scan, Quick/Standard scan in Simple UI) scan the files in System Volume Information, but Thorough scan in Simple UI doesn't... right?
What if you choose "Folder selection" in Simple UI (with Thorough scan) and select the System Volume Information folder only - does the scan finish immediatelly?