Problem with Ipo-animation

Hi!

I have got a problem with an ipo-animation in game. I tried to make a door that can be opened and closed when you press a key. I built it into the FPS-template by Social using Blender 2.44.

It allmost works perfect: You “walk” close to the Door, press E and the Door moves up, you press e again an it moves down again. But if you press e a third time the door moves up and flips down. You can still close it by pressing e, then it flips up and moves down normaly.

Here is a screenshot of my work:
http://img178.imageshack.us/img178/9826/doorscreenzy0.png

Waiting for help, Cody