Final update, and a solution of sorts.
Nothing I've tried fixes the problem in the proper way, i.e. preventing drag windows from being disabled in the first place. It just so happens that one of my searches stumbled upon a simple exe (author currently unknown) that resets the option.
So I've caved, I've downloaded this exe and used task scheduler to run it every ten minutes.
You know what, I'm torn, this fixes the problem but it's just wrong, this is the only problem I've not been able to fix correctly and it still winds me up!
Andy,
