Problem on Unreal Tournament 3

I have a big problem on Unreal Tournament 3 (purchased via Steam) ... I say right away that I installed all the patches and that the game is in version 1.3.

1st scenario: No. 1 PC (Pentium 4 530, 2GB RAM, XP SP2, Geforce 7600GT, screen resolution 1280.1024)

The game starts normally and I see the main menu. So far so good ...
But after loading a map in instant action, just as the map is supposed to begin to appear, Bam! black screen and return to windows with an error message ... There was just one or two times I had the right to the emergence of a furtive picture before it crashes.
By campaigning against everything seems to work properly.

2nd scenario: No. 2 PC (Pentium 4, 2GB RAM, XP SP2, Geforce 8800GS, screen resolution 1680, 1050)

It begins the same way: the game starts normally and I can navigate the menu without problem . But then in this case, either campaigning or instant action is nothing more and is the black screen every time ...

Has anyone already encountered this problem and would it solve?

Thank you in advance.

Two Nvidia cards, drivers origins?
If so download the latest drivers.
Otherwise you can try to pass a memtest on the ram to see if there are errors.

I verify that I have the latest drivers for the card

The latest drivers are able Nvidia 180.48 I believe.
Otherwise, you tried to play instant action without patches? Otherwise trying to play through patches one by one, ie, you installed the normal you try to play, if it works not you put 1, you try to play, etc