When I received the NB-1C, my main test rig was tied up with another review, so I decided to use my old EP-8K7A/T-bird 1.4 system. However when I went to mount the NB-1C onto the AMD Northbridge, I found it would not fit due to major interference with a large capacitor. The next day I tried the Thermalright cooler on two older Pentium 4 boards I had at work (Soyo and Gigabyte) but the mounting hardware was not compatible.
Bottom line: check the NB-1 motherboard compatibility listing on the Thermalright website to see if your particular motherboard and chipset is supported.
Overall, motherboard compatibility appears to be good (for the chipsets supported). As you can see in the following picture, several different mounting options are included to provide as much flexibility as possible.
The SS inserts on the left are typically used with AMD motherboards while the various wire mountings are designed to work with Intel motherboards.
Once my main test rig with an Nforce2 chipset became available, I had no problems mounting the NB-1C cooler.