I'll try and explain more clearly
Limitation of this hack:
It will only check for the file name, eg abc.php, if you have abc.php?a=bc they will count for the same, whereas if you edit online.php you can give them different locations.
Posible Limitation of vB, as it stands you can only have one file with the same name recogised, with hacking you should be able to get it to recognise paths as well.