1998 Honda Accord Multiple Failed CV Axles

My problems started with a failed outer CV joint on the passenger side (typical cracked boot, grease all over). I purchased a new axle half-shaft and installed it. The car seemed fine for a time (maybe 75-100 miles), but soon developed an unhealthy vibration in the front end, worst under acceleration and maintaining highway cruising speed.
My axle shaft has a lifetime warranty, so I replaced it a ~three weeks after installing it the first time. This shaft lasted another ~100 miles before it too failed.
I had some other work to do on the car, so I figured I would replace it once more just for kicks. Sure enough, after 50-75 miles it has begun to vibrate again. Any ideas what could be destroying my CV joints! This is driving me crazy!

There seems to be more play in the right side CV axle than there is in the left side (left side is original), even just after installing a new shaft. Tranny or differential problem, maybe?

Many thanks in advance!