Radius proxy and attribute class 25

Hi all, I have setup fr (2.1.6) proxy against MS NPS it works fine and even chalenge-responce works great. But now i have one problem NPS sends attribute 25 (class) back to the fr server and it's seems that fr brokes that/or dont accepts that attribute class. When class should be eg. OU=Test_users fr says something like ?=xxx?Xx++xXX (in clear text). Any suggestions? Br, Ville