OK I've analysed the mod and it looks like it has some really big textures in it.
According to Microsoft any DirectX 10 card must support textures of at least 8192x8192 in size (there isn't a limit I know of for DirectX 9 but it was usually 4096x4096).
This mod contains a texture that is twice that size. Some cards support textures that size some don't.
You'll need to unpack the textures, edit the roads_combined_01_d_co.tga.dds file, reducing it by 4, then save and repack.
Edit: By the way I think the flickering texture is due to the mod having normal maps with too much detail and mips. It's very difficult to generate proper mips for normal maps. It's not simply a case of scaling down the original normal map as that can lead to artefacts.