Momodot,

Somehow D/S and Poser use different coordinates.
Hence, if you export/import between these two, you get the jumpy long neck and jumpy eyes:-)
So, the best is to follow the export first, FS, import back rule.
It is all nicely illustrated on the "How-to" videos.
Pls private message me and I'll give you the URL  to the videos (otherwise I'll be kicked out of Rendo).
Laslo