Apple Script: Script works in Editor but not in iTunes

Question

Ok so I have written/cobbled together other peoples scripts to make my own script but now it will only work in Script Debugger 4.5 or AppleScript Editor??? When I exicute the script in the editors it works perfectly, but when its saved and added to the iTunes script folder it all works except for one part.
This part is supposed to duplicate the iTunes file then open it back into itunes, so I have two copies of the file (so I can alter one). Now in itunes everything works but it seems to be skiping over the open command??
any help would be appreciated
to DuplicateItunesFiles()
    set trackTitleList to ""
    tell application "Finder"
        repeat with i from 1 to the count of the selected_track_files
            set currentFile to item i of selected_track_files
            set currentTitle to item i of track_titles
            set trackTitleList to trackTitleList & ", " & currentTitle
            open (duplicate currentFile to folder of location_file)
        end repeat
        if trackTitleList is "" then
            display dialog "Sorry, couldn't duplicate your tracks."
        end if
    end tell
end DuplicateItunesFiles

Answer 1

Ya sorry about that, the script is long and poorly made so I didnt want to scare people of haha.
Here is a link to the script I am having trouble with (Version 5.2): http://pastebin.com/dGsHifZM
and I'm not sure if this is helpfull but here is an older version that works...in both the editor and iTunes http://pastebin.com/chb19KNQ
Errors: I get this error only sometimes:
Can’t get «class cTrk» 1 of «class pPla» of application "iTunes".
Edit: Can I not edit my origonal post to add the links into it?