It is more than far down enough and in fact I've already been looking for a Poser/Python reference. Silly me just never checked the "tutorial" section in your shop.

Apart from that I would have been ok to cash out some for a script like that anyway so now I get a script and the just ordered manual. Seems like a good deal to me :)

 Back to the script - I ran a few tests and it seems that just beeing in the "layer" tab already is enough to break the exported bvh. Whenever I load a scene which exports fine the export looks like the regular export when I activate the tab without making any modifications. Now if I click "include" for a layer the result is totally strange and the avatar is shooting forward. Going back to the keyframe tab fixes this problem.

So it looks to me the problem really comes from Poser and not the script. And I am hoping your book will explain how I can activate the keyframe tab again - ...or you might add it to the script already ;)

However to make sure I did an uninstall of Poser and reinstalled it from the scratch, including the current service pack and the problem still persists.