x permission lost on Windows merge

Hi All,
   I was just on IRC chatting about this issue. What I'm finding is that 
if a merge happens on a Windows git repo the x permission is lost, 
example (filename changed):

filename.pl

----------------------------- filename.pl ----------------------------- index 0388de4,94d7e76..9c31830 mode 100755,100755..100644

As you can see, both of the modified files are 0755 but the merged file is 0644. I know windows files don't have the x permission, which explains why the newly created merged file would be missing the x, but surely with filemode = false the behaviour should be to carry over the x from the two modified files?

This is causing me problems when the merged file gets pulled back onto Linux systems where it needs the x permission.

Lyle