I've found that on some onboard "intel" graphics cards when I've created a level that used multiplyx2 blending the level appears all white as if it is not textured.
Yes, this sounds like a Blitz3d bug I reported which has been routinely ignored for years, as with many Blitz3d bugs. I found that putting a cubemap on any texture stage but stage zero made the entire mesh render pure white on some videocards. I haven't experienced the same thing with Mod2x blending but it wouldn't surprise me.
Of course with a cubemap, you're often using Additive blending, so it doesn't matter once you're aware of the bug. You just switch the cubemap to stage zero and off you go. With Mod2x blending, you can't really do that, I guess.
I'm not sure what ATI series of cards is in the same line as the GF2 though, so no idea on that front.
Well the Radeon 8x00's were equivalent to GF3's, so I'm pretty sure the 7x00's were on the same level as GF2's. Back then, of course, Radeons were a bit behind the times, so I'm not sure if they support Mod2x or not.