R help - Mar 2009 - Bias correction for random forests?

Hi,

Way back in 2004, an update to randomForest added an option 'corr.bias'.
The explanation was a bit vague, but it turns out it improves RF's 
predictive fit with my data substantially. But I am having trouble 
understanding it.

Does anyone know what this 'bias correction' actually does? Or what the 
justification for it is? Or when it would be necessary? Is there a paper 
I can look at?

And is the feature likely to emerge from 'experimental' any time soon?

Zhou Fang