Hello all. I just purchased RF 6.5 but after installing and trying to launch, I get the following error message:

Error: D3DERR_INVALIDCALL
FILE: .\DXEffect.cpp
Line: 850

I installed the latest drivers for my video card and verified that I am running DirectX 9. My system config is:

Win XP Home Edition - service pack 3
Dell Dimension 2400 desktop
Intell Pentium 4 - 2.40 GHz processor
1 Gig RAM
DirectX 9.0c (4.09.0000.0904)
45 Gig free space on hard drive

ATI Radeon 9250 video card with 256.0 Meg memory
Display mode: 1152 x 864 (32 bit) (75Hz)
DDI Version: 9 (or higher)

Can someone please tell me how I can resolve this?