http://www.newscientist.com/article.ns?id=dn6934

"Some iterations of the models showed the climate cooling after an injection
of CO2, but these were discarded after close examination because the
temperature fall resulted from an unrealistic physical mechanism, says
Stainforth. In these scenarios, cold water welling up in the tropics could
not be carried away by ocean currents because these were missing from the
models.

There are no obvious problems with the high temperature models, he says. The
climateprediction.net team were left with a range of 1.9°C to 11.5°C. "The
uncertainty at the upper end has exploded," says team-member Myles Allen."

Discarded only the cooling models? Sounds like fudging to me...