I got mine to 2.2 (nearly) no worries, but the truth is that every single CPU is an individual, with individual defects and individual maximum settings.
Remember too that the higher you get, the closer and closer you are to the breaking point (at which your system won't run properly) and the less and less performance increase you'll get (it's an exponential curve), so i genuinely don't believe it's worth pushing the FSB to the absolute max.
<A HREF="http://www.anandtech.com/mysystemrig.html?id=18108" target="_new">http://www.anandtech.com/mysystemrig.html?id=18108</A>