Walkcycle and ipo problem

I made a skeleton for human model and then walk cycle using keyframes. In 12th frame I rotated left leg and right arm forward, right leg and left arm backward for it to walk kinda natural. Then in 18 frame a standing postition and then in 26 frame I copied/pasted flipped pose from 12 frame to get it cyclic, and in 42 frame pasted 12 frame. It animates cool but when I entered IPO window and looked at curves of left arm and left leg I got a bit confused. These curves are almost the same while I believe there should be some kind of ‘translation in phase’ because when I rotate left leg forward, left arm should rotate backwards. Blender seems to animate it properly but when I export it to other format and animate it in another modeler, it goes like IPO curves say. Here’s a screenshot:
What could be the problem?