Ian, this is rediculous, stop nuking my posts, please.

Ok, once again, with no reference to any manufacturer this time.
A manufacturer of aftermarket manual hubs says the following on their site as one of the benefits to their product:
"Better 4WD... performance when the hubs are locked. Works in reverse and compression braking. No slippage or partial engagement / disengagement problems"

I guess there's something to it, nothing I worry about though.

Brent