I'm sorry if I missed something earlier, but I think what I'll say next does not help the way you'd like it

I run EB on a laptop:
Centrino 1.6 GHz
1 GHz DDR (2x512 Mo)
ATI 9700 with Omega 3.8.273

And it perfectly works (campaign map on 1024x768, battle map on 1400x1050). No texture bug at all, and this has been so since the first time I launched my EB game.

Hope you'll get this sorted out anyway, and maybe that is in fact related to Omega, but from what I've experienced so far, it's not...

Good luck!