zip Toast creates empty zip file

Hi, this script works just fine on other file formats, but when it comes to zipping a Toast (10) file, the zip file created is empty (size: Zero bytes).

Is there anyone that knows of a workaround?

set SourceFile to "/Volumes/HD2/sjungarna_inspelningar/199 - Mohedaskolan/199 - Mohedaskolan.disc"
 set DestinationFile to "/Volumes/HD2/sjungarna_inspelningar/199 - Mohedaskolan/zip-filer/199 -"
 set SourceFile to quoted form of SourceFile
 set DestinationFile to quoted form of DestinationFile
 do shell script "zip -r -j " & DestinationFile & " " & SourceFile & "* -x *.DS_Store"