Poser 7 issue

I make my animations in Poser 7 through say 50 key frames with every 5th or 6th frame a movement. It all looks great until I play it back in Poser and the limbs just go wild, jumping all over the place and twisting everywhere. What causes this and how can I get it to not do this?
I have made a few animations that worked great and are in world now. I don't think I have done anything different.

Just made three simple animations, sitting and talking, that went well but the fourth went crazy again, in turn driving me crazy. All about the same then one arm went haywire, twisting around the back and head.
These all started with the poses in Poser (after the T on frame one of course). All I did was some simple adjustments here and there every 5th frame or so but once again on playback within Poser it gets "interesting".

In the keyframe editor, select all of the first keyframes and press the "Break Spline" button. This tells Poser to take the simplest tween path between all the keyframes in the designated limb. Hope that helps!

That sounds like it would work, I'll try it after work.
Thanks

You may also need to change the interpolation type beween key frames to linear if breaking spline does not fix things.