iTunes "?" error

Hi, I've been working on an AppleScript that sets the comments of specific songs to the artist name and album name in both Finder and iTunes. This uses a text delimiter, which I'll need for another script, that separates the artist and album names into two separates items.

It all works fine except Finder keeps changing the question marks from the titles of song files and folders into underscores. For example, the songs in the album "Are You Experienced?" automatically get dropped into a new folder called "Are You Experienced_" . I have worked on this for two days straight and I am absolutely stumped. Does anybody know how to keep the question marks in those titles? I'll try any suggestions you have!

Don't forget to highlight the songs in iTunes before running the script!

property seperator : "/"
tell application "iTunes"
     set curSongs to every track of playlist "Library"
     set thisSong to curSongs
     set theCount to 0 --flag duplicates with a comment
     repeat with thisSong in selection
          set theCount to theCount + 1
          get theCount
          if theCount = 1 then
               set lastSong to thisSong
          else
               set fileloc to location of thisSong as alias
               set details to artist of thisSong & seperator & album of thisSong
               set comment of thisSong to details
               set details to my list_to_text(details, return) as Unicode text
               tell me to fill_comments(fileloc, details)
          end if
     end repeat
end tell
set AppleScript's text item delimiters to {""}
beep

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to fill_comments(fileloc, details)
     tell application "Finder"
          try
               set comment of fileloc to details
          end try
     end tell
end fill_comments
on list_to_text(details, return)
     set AppleScript's text item delimiters to "/"
     set txt to text items of details
     return (txt)
end list_to_text