Stadium maker needs help - Maybe Anamorph can helps me

Hi everyone, I hope there isn't any problem to write in English, I don't know how to write in german...

The doubt will be explained considering that the reader has some experience with Stadium making, if you don't have it, you may get kinda lost in my words...

I'm the stadium maker responsible for the Home Park (stadium of Plymouth Argyle), my next project will be Elland Road (Leeds United's home ground), but despite the fact I've released a stadium properly, this time I'm facing a really strange problem that I can't solve. Parts of my model are too white, like the diffuse texture (lightmap) isn't loaded properly.

The result in game is like this:

http://i.imgur.com/zKr5lsX.jpg

As you can see, most of the roof parts are presenting that issue, you may have think that I did something wrong on the material settings or something, but check it out what happens if I delete the functional parts and let only the prolematic ones...

https://i.imgur.com/xL78xoi.png

As you can see, it works perfectly.

Before continue, I want to say that my model is heavy, I made the stadium fully detailed. It has around 250 objects.

What I've tried so far:

Check all the material/texture settings and map settings
Reduce the size of all diffuse textures to max 1024x1024
Reworked most of the ambient textures to get smaller texture files
Paint the background of all diffuse textures with light gray color
Verify vertex color creation
Groups are right
Test with Stadium Server and with Anamorph's method of including stadiums

Nothing changed the problem, please, is there anyone who knows what's happening? Im working with this stadium for 3 months and I'm almost quitting because of this dead end. Is there any limit of objects know on stadiums? Cause it seems to be that as you saw in my tests above...

Hope someone answers, good bye and thanks.