Apple Event Timeout; how to stop timeouts in QuickTime

I'm running a AppleScript to drive QT 7 Pro to make image sequences for me. It's all fine but with the newer 36MP cameras I have found that I get an Apple Event Timeout, but only on external Firewire 800 or USB 2 drives. On my internal SSD it's fine.

In the code, I have a with timeout function, but it's not working. Any thoughts on how to stop the timeout?

The timeout below in the code is huge because I normally leave the script to run overnight on a 1Tb volume looking for anything recently added and sequencing it. It works perfectly on all drives (internal and external) providing the files are smaller (16Mp or below). My new D800 36Mp cameras are creating timeouts though but not on the internal SSD of my Mac, but on the external drives I use in the field.

17" Mac runs 10.7.5, 8Gb Ram, 512Gb SSD internal. External drives normally Firewire800 Rugged LaCie.

tell application "QuickTime Player 7" -- if you're running 10.5 or less it should be "QuickTime Player"

-- possible update to use quicktime settings file rather than 'most recent settings'

with timeout of 3600 seconds

set theMovie to open image sequence (FirstJPEG as text) frames per secondtheFPS

end timeout