Custom Skyrim Armor distorted ingame

[Sanchez92]

Hi all i have a very very very annoying problem.

I made a new helmet for the game, but when i try to put in a nif (i export the model in obj, then i open the vanilla mesh and i replace the model because the Niftools doesn't exists for 3dsMax 2013, f*#@. )

 

In Nifskope i see this, seems ok

 

http://i299.photobucket.com/albums/mm314/Redigondor/dioinsulso_zpsa70dff74.png

 

 

 

but ingame i see that s#*!.

 

http://i299.photobucket.com/albums/mm314/Redigondor/TESV2013-02-2503-10-24-69_zps6774aa3a.png

 

 

 

Any help? are three days that I try to solve this problem. please....help :C

 

 

 

EDIT: Second Issue

 

Sometimes (everytime in the last 3 days) when i import a new mesh in nifskope, they are distorted, some parts are missing and s#*! like this....any solutions? :C

Edited February 25, 2013 by Sanchez92