I've been working on a 3ds Max 2010 version of kW X-port (with some nifty new features, too -- I'm calling it "1.4.0"!)
Unfortunately, when time came to do the x64 build, it just wouldn't work. After some investigation, and building a sample exporter direct from the Autodesk SDK (all their code), that sample also crashes when exporting.
It seems that something is broken (again!) in the IGame exporter interface. 1.4.0 already moved away from IGame for effect/shader export, because IGame would not accept some perfectly valid shaders; it appears that I may have to totally move away from IGame for this to actually work out. That's annoying, because IGame is supposed to make dealing with both Physique and ISkin much easier -- I'm not looking forward to re-writing all that code!
That being said, I'm hoping to get a 1.4.0 beta installer for 32-bit 3ds max 2010 (and 2009, and 2008, and Max9) up by the end of today.