Hair going crazy

I have a charactor with hair but when I try to pose him his hair goes crazy. My question is do I just ignore it and rebake the hair after I have finished animating him going up stairs or whatever? or am I doing something wrong/ missing something?

A bit of a bump but also a chance to expand my question, I have also noted that the clothes that are parented to the charector are also not following right. They move fine if I animate the him standing in one spot (as does the hair) but if I try to move him on a step (38 frames later) it goes haywire. I have set posses in the pose library for left/right leg up/down etc, which work fine on the spot. Have I mucked up the work flow (surely not?!) by dressing him and giving him hair before animating him? I’m a bit of a nuub on character animation as I’m sure you can tell and need a bit of clarification… Thanks very much for your time btw.

This kind of sounds like something that happened to me once. Do you have hair dynamics turned on when you are posing? If so, try turning it off. Turn it back on when you are done, before you render.