Antonov AN-22 tail-heavy

I seem to have a talent for finding planes that are "almost" wonderful, except for one flaw.

The plane I'm referring to can be found at:

http://www.wspilots.com//?page=4&action=file&file_id=1737

The problem is that if you start FS and select it and go to fly it, you'll find it sitting at the end of the runway. Before you do anything, it sinks at the tail and crashes with its nose pointing straight up.

I dumped half the fuel and all the cargo, then killed the parking brakes and hit the throttle before it could misbehave. Takes off and flies nicely, nice paint job and has 4 engines, each with a pair of counter-rotating props.

Anyone know what I can tweak to cause this problem to go away?