Burn-in image using a DVR

any more than 15 minutes would be enough...

actually 5 minutes should do it.

OP,
Yes, we were joking.
the LN40A550 is an LCD.
You have absolutly nothing to worry about unless you plan on leaving it paused for a year or two.
The worse youll get by leaving it like that for hours and hours is a little image persistance. And that probably wont even happen.
don't worry about it at all. thats one of the plusses about LCD.

Coulda swore I saw you say something like "Having a sense of humor is a virtue. Try it. ".

yes I have that model, I've left it on for two days by accident, paused on a program from my TiVo. No problems since it's LCD.

I apologize. We are on the opposite sides of the great plasma-LCD debate but I respect your position and its consistency. A smiley face would have helped but it is still my fault. Sorry. Post deleted.

Well LCDs can burn in, but usually only cheaper quality ones. Technically it's called Overdrive, not burn in.

That said...you have a quality LCD and should have nothing to fear. Maybe if you keep it on a for a few months straight you might get overdrive...but who knows.