Well, as long as you're not losing half the image or framerates when it reads it as 32, doesn't sound like there is a problem. I don't think there are official voodoo drivers for anything non-9x, so it's probably just a quirk because of that. If there was something actually wrong, you would notice it in the games since I'm pretty sure each chip gets a dedicated 32 MB, since everything has to be doubled.(in which case, it's basically an effective 32 MB, I think it comes out a bit higher since not absolutely everything is doubled, but well under 64)