Files saved via the "Archive the artifacts" mechanism lose their file access bits.
In the workspace, the file is:
-rwxr-xr-x 1 jenkins nogroup 577 2012-06-30 09:23 XXtool
in the archive dir, it shows up as:
-rw-r--r-- 1 jenkins nogroup 577 2012-06-30 09:32 XXtool
There's no way that I can see to preserve the file permissions.