MkII Strobe Sync Speed?

I recently shot a hockey tournament where we used self-installed strobes and pocket wizards to light the rinks. One of the other shooters told me his MkII could handle a 1/500 sync speed with the strobes, but I just looked up the spec, and see it's the same 1/250 as my 20D.

Was he wrong, or did I misread the spec? Or, do I not understand how sync works with strobes? He was able to use 1/500 shutter speed, but when I tried, I got obvious shutter curtain problems (dark band) and had to limit my shutter to 1/250.

Thanks,
Dennis
http://www.pbase.com/d​mwierz45/sports_shots

The sync speed is usally a conservative number. Cameras can usually go faster, but 1/500 IMO is really pushing it. Your colleague may have been thinking of the original 1D.