I had a problem with a pair of Mavic D521 about the same time period as the OP mentioned
the cause was a worn rim die tool in the Mavic factory
I was told (by Mavic) that the worn tool meant the rim extrusion was slightly oversize, and when they fitted the eyelets there was a lot of stress concentrated in the eyelet drillings
on both my rims (built properly by cycle surgery in London) the rims started cracking around all of the eyelets, I was offered some Sun rims as an alternative at no cost and did not use Mavic for many years after that
however, as a professional mechanic I have since built many pairs of wheels using Mavic rims for road, CX, and mountain biking including XC, FR and DH and no problems to report for either my customers or myself
I current use Mavic A319 rims on my commuting bike which gets beaten through potholes, drain covers and kerbs and the rims are just fine