After some investigation into AGP clearance specs and the like, Kyle has rendered a verdict on who messed up, Epox or VisionTek. You should read Kyle's account and look at the pictures for yourself, but he says Epox is the guilty party. Unfortunately, that doesn't give those affected by the problem many options. Returning the VisionTek GeForce4 for another brand probably won't help, because:
it is very likely that all or many of them will have the same problem. We has of yet to prove this, but almost assuredly, the will all follow the NVIDIA reference design as does the VisionTek Ti4600. This brings up all sorts of questions about restocking charges etc...Not fun. For what it's worth, GF4 MX cards don't seem to be affected. I have an Abit Siluro GF4 MX 440 card here installed in an EP-8KHA+, and it fits fine. But then, it's a lot less card than the GF4 Ti 4600.