If it is just not RealPlayer, then uninstall all DivX codecs and install the latest DivX 5.2.1. DivX has fixed the Explorer crashing issue with their latest release.
http://www.divx.com/divx/download/
Or
Install 3ivX D4 4.5.1.
http://www.3ivx.com
It can play DivX, XviD and 3ivX.
