You'll need to do a bit of debugging. The first place I'd look is in the SQL statement that populates the varDeleteFileList variable; if you run this as a query in the Management Studio do you get a result set? If not, that's your problem.

If you do, try adding breakpoints in the script code just before the Dts.TaskResult line (for instance). That way you'll be able to see which (if any) values are being passed along.