The AP with some MRAP rollover numbers

There have been at least 66 MRAP-related accidents from November to June, according to Defense Department statistics. Nearly 40 of those involved a rollover caused by bad roads, weak bridges or driver error.

"We're certainly concerned," said Brig. Gen. Michael Brogan, the Marine Corps officer who manages the MRAP program.

(Mercury News)

Afghanistan is more likely than Iraq to have bad roads and rough terrain, from what I've read. Or perhaps I should say Afghanistan has more bad roads and opportunities for rollover accidents. It is possible that heavier use of BAE models in Afghanistan resulted in the warning focus on BAE vehicles.