Have a look at a pic of the Ati Silencer 5. See the little plastic nubs for the screws around the fan housing? The bottom one smacks into the HSF for the NF4 chip on the DFI Ultra-D. You can put the vid card + Silencer into the other full length PCI-E slot, but if you have a medium to large card in the last PCI slot (such as an Audigy 2), then the nose on the fan hub hits the back of that card.
Simple solution - if you don't mind scrapping the warranty on your new cooler - grab a Dremel or file and eliminate that bottom nub from the fan housing. The cooler will then be clear of the NF4's HSF. The fan housing is rigid enough to hold together without that screw, but you can apply a bit of glue there if you want to.
We now return you to your regularly scheduled foruming 😛
Simple solution - if you don't mind scrapping the warranty on your new cooler - grab a Dremel or file and eliminate that bottom nub from the fan housing. The cooler will then be clear of the NF4's HSF. The fan housing is rigid enough to hold together without that screw, but you can apply a bit of glue there if you want to.
We now return you to your regularly scheduled foruming 😛