Problem with Acrobat compatability list returned from ID CS2

I’m having some trouble with a list retuned from InDeisgn CS2. See the script below, when i test this i my application it returns a value like this “constant****Ac50”. Whicth is weird, because when i test the same from the Script Editor it returns “acrobat 5”.

Now, I might just have missed something really obvious, but please help.

tell application "Adobe InDesign CS2"
	set PDFcompatibility to acrobat compatibility of every PDF export preset as list
end tell
set contents of text view "tf_summary" of scroll view "summaryContainer" of window "main" to item 1 of PDFcompatibility as string