From www.HardOCP.com :
VisionTek GeForce4 Ti4600 will not fit properly into the AGP slot due to capacitors on the card and mainboard binding. While this picture shows the card a bit cocked, trust us, the caps on the mainboard were preventing proper AGP card insertion.
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It is our opinion that the VisionTek Ti4600 is not outside the AGP 2.0 specification in regards to the data above.
According to AGP2.0 specifications the spacing around the AGP port on the motherboard isn't really up to the specs. Bit of a messy motherboard configuration by Epox...
Possible solutions from HardOCP :
The first solution, and the correct solution, would seem to me to be that EPoX should replace your mainboard with one that complies to industry standard AGP specifications. They do state the two boards mentioned above to be "ATX" spec. Seeing that these ATX boards have AGP slots, they should abide by the AGP 2.0 specification. Then again, that is just our opinion.
The second solution is this. Return your GeForce4 Ti card, as it is very likely that all or many of them will have the same problem. We have yet to prove this, but almost assuredly, they will all follow the NVIDIA reference design as does the VisionTek Ti4600. This brings up all sorts of questions about restocking charges, etc...