Blank screen and particles not visible

Hello!

Some people is having problems with the game I'm doing.

2 have problem with the particles: One is telling that he is not able to see any particle, the other told me that he saw an explosion but very very small (the explosion itself should fill the screen). One has a Nvidia 6200 and the other Nvidia 6800, both with new computers.
Another 2 can see the first message in the screen writing "loading...", but after that, when it is supposed to appear the menu, they are seeing a blank screen. This part is basically a copy of Ecksdee. One has an ATI card, the other one I don't know.

I have tried the game in my old computer which has a very old Nvidia (TNT2 Riva Ultra 32MB) and doesn't have this kind of problems (only performance problems =P). I was thinking that maybe is related with the libraries or the loaded plugins...

My CS & CEL version I think are from 2006/07/03 (I don't know how to check but the libraries were created this day)

Any idea of what can it be?
Maybe I should move to the new releases changing the win libraries from 0.21 to the new ones?

Thanks!