The rim width is also a limiting factor. If the rim is too narrow for the tire, you increase the likelihood of pinch flats or ever tire roll-offs. Sheldon has a chart on his wheel size page: http://www.sheldonbrown.com/tire_sizing.html

MA2 and MA3 are the same rim but the MA3 has the hard anodized surface. The MA2 is out of production. As Jobst Brandt points out, the ano treatment is done before the rim is joined, so the twisting necessary to bring it into a flat hoop cracks the ano layer. Now you've got less structural material sitting underneath a layer of cracked aluminum oxide. Nice work. This is what leads to spoke pull-through. Plus I think it's a single eyeleted rim rather than a full sleeze where there is an eyelet on both the inside and outside surfaces of the box section. Likewise they have some history of the sidewalls separating from the rim base.

Mavic recommends 100kgf of tension which isn't unusual but other manufacturers will let you go higher. After smashing my rear, I rebuilt it at 110kgf because I'd rather worry about spoke pull-through than another crushed rim. Of course, I have no hard proof that a more highly tensioned wheel wouldn't have also gotten ruined.