I have this problem with weapons (this pic is of Doom gun but it happens with some UT default and U4E weapons too): It happens with both directx and xopengl or other renderers.
In other older installation of UT I have here, all works normally: Both copies of UT seem to have the same video configuration. One is v.432 (the working one) and the other is 451b, but It shouldn't be this the problem.
So... I yet tried to copy textures from older (working) version to the "broken" one, overwriting all textures, but nothing has changed. So, it's not a matter of texture I suppose

What can be the cause? And the solution? I can't identify the difference in the two versions of UT, to solve it.
Thanks!