The Arctic Cooling VGA Silencer will not fit on an IS7 board with the new revision heatsink. (larger blue/green, mini-zalman wannabe). The big blue chunk of plastic that is part of the rear retention clip of the VGA Silencer just sticks out to far. You might be able to make it fit if you hacked up the blue plastic, I didn't want to do that though so I'll be trying a square NB cooler and I believe it will just barely fit between the VGA Silencer and my Zalman 7000. It is a bit disapointing though after I went to the trouble of making sure I got the newer heatsink to have to replace it. But I've been wanting to try that Swiftech NB cooler, it just seemed to expensive until I had another reason to go for it.
I don't see this being a problem with MOST boards, but the spacing works out to totally screw up the fit on my IS7. I'm really not sure if this will be a problem on any other boards, but it definately seems possible on boards that put the NB cooler especially close to the AGP slot. It doesn't have to be a LOT closer than normal, a few millimeters can make a world of difference.