I haven't any skins other than the default skin and I don't appear to have that problem. There is only one file in my skins folder the default and no additional bmp files.
Perhaps I didn't have the sensitivity of the scan set high enough to trigger this
Update:
Having set my Standard Scanner to High and scan archives, I ran the Standard Scan again, I too get this listing. Since my last scan was a boot scan, and my default scan was set not to scan archives, this may be why this was not picked up.
An explorer (right click ashquick.exe) doesn't pick it up either because it is not unpacking the 'ad-aware SE default.ask' file in the skins folder.
It would appear that the 'ad-aware SE default.ask' file is some form of archive file, whose contents are password protected.
The strange thing is how does it display a list of .bmp files within the 'ad-aware SE default.ask' file if it is password protected. As some have mentioned, why would ad-aware want to password protect a skin file