ExportIng QuickTime movies

I’m having a problem with exporting movies using QuickTime. The script that I wrote is a very simple batch conversion script that converts mpeg movies to mpeg4s. The program works fine except that all of the newly saved movies are off screen slightly to the right. When I save the movies using just Quicktime, the saved movies come out just fine. I did notice that a grey background progress indicator comes up when I use my script as oppose to the white background progress indicator when I use just Quicktime. Is a different program doing the conversion in applescript? If so, how can I switch to the one being used by QuickTime. I’m using Tiger which includes Quicktime 7. I did the Quicktime update, but I still didn’t have any success.
Thanks in advance.

on run
	set thempegsfiles to the (choose file with prompt "Choose MPEGS to Convert to MPEG4 " of type {"public.mpeg"} multiple selections allowed "true")
	repeat with acoolist in thempegsfiles --used to loop through the list
		tell application "QuickTime Player"
			open (acoolist as alias)
			set mystring to acoolist as string --this sets the 'type' acoolist to a string 'type', i.e. coercion
			set newstring to mystring & "-new"
			if (can export movie 1 as MPEG4) is true then
				tell (export movie 1 to newstring as MPEG4 using most recent settings)
				end tell
				display dialog "Can't Export as MPEG4 Movie"
			end if
			close the front window
		end tell
	end repeat
	tell application "QuickTime Player"
	end tell
end run