Yup, heatsink too large. I got an Asus ENGT430 and it juuuuuust fits. But the fan was too noisy. I was planning on running Ubuntu with XBMC on a microserver, but in order to do this you need to use an NVidia card for GFX acceleration, it don't work too good on AMD. But as I said in the other thread, I'm going to rather do another build for an HTPC as even the Microserver itself is too noisy for my liking.