I think these files are here to stay.
I found this useful thread
http://www.aximsite.com/boards/showt...=flash+from+SD that explains how to trick the ROM installer into installing the same version or an earlier version.
I flashed A03 and A05 and the files are still in BIS! System settings confirmed that it reverted to A03.
So unless I find some handy utility that cleans out everything, I'll just have to live with two useless folders sittin in the BIS taking up a few MBs.
Thanks for the suggestions.