I noticed another issue, that is related to layout.ini - VirtualStore feature of Vista.
There is a 64 MB data file in Program FilesArena\Book\mainbook.abk ( Chess opening database) , managed by my layout.ini. This file has last access date 3rd January.
The reason is this file is not used at all, but other - modified - copy in my VirtualStore.
( Users in Vista are able to modify files in Windows or Program files even without write permission.
It is Vista tricky solution, redirecting the write to VirtualStore folder in \Users\user\ area.)
Note that I use Vista under non-privilaged account.
That file is than used for given user instead of the original file.
The illusion of using the original file is so good,
that other parts of Vista are fooled by that.
In my case it is easily avoided by LastAccess timestamp.