If its a Barton core, then 2.2GHz should be easy at 1.65 - 1.70 volts.
I have three bartons at home, a desktop 2500+ that I got several months ago that runs at 2210 (210mhz FSB) completely stable.
I have a second desktop barton that I bought before I heard about the overclocking of the mobile parts, it will just barely do 2000 (200FSB) and I don't know how stable it is, its sitting on my book case right now.
I have a third which is a mobile 2500+. I haven't primed 95ed it yet, but it runs at 2.5GHz very nicely. I suspect I'll have to back off to 2.4 GHz to be Prime stable.
Will post when I get a chane to prime it.
ImagineDude