Permissions editor app broken in 10.5.8

I wrote an apple script to change permissions on files. It worked great until 10.5.8 came out or it could have been the security update. I save it as an app and drop files on that i want to change the permissions on.

Here is the script.

on open (theseFiles)
	repeat with thisFile in theseFiles
		do shell script "chmod -R 777 " & quoted form of POSIX path of theseFiles user name "MacAdmin" password "Password" with administrator privileges
	end repeat
end open

Model: MacPro
Browser: Firefox 3.5.3
Operating System: Mac OS X (10.5)

Try . POSIX path of thisFIle . (instead of theseFiles)? Maybe you just recently started dropping more than one file at a time? It probably would have worked despite the error since POSIX path of {someAlias} works just file POSIX path of someAlias.