Problem exporting 3ds models

[Stygs 25]

I recently run accross a annoying problem in 3ds max that I cant figure out:

 

Some parts of my models gets resized when exporting:

 

Basicly, I imported the CnC4 Reaper, split the laser gun from the obelisk on its back and want to export it.

If I use WWskin or dont link the new mesh to anything, it works fine. But if I link it to a bone directly (no point in using wwskin since it it only affected by a single bone), it gets waaaayyyy to big in the w3x.

 

 

Its like the model is 50% bigger than it should be.

 

I also noticed that this only happens if I use an existing skelleton for the model - if I export the whole model including the bones, it looks fine.

 

 

Any idea what exactly is causing this and how I can prevent if?