I have the same problem too. Especially in the sewers and the Death Realm, not much in hydlaa and Oja. The problem only happens when I move my char or try to click on something: at some point it was crash after crash with one of my chars everytime I was trying to make him move. I restarted and waited, doing absolutely nothing for a dozen minutes and it didn't crash actually. But as soon as I tried to move the char the client crashed.
The drivers of my graphic card are up to date and my specs are more than ok (I could run more than one client fluently!)
I've tried running the updater with checkintegrity but nothing failed the check. I tried tuning down the settings too, following StitchedChin advice, but that didn't help.
Everything was fine until today, so I don't think it has something to do with the recent update.
Finally, I've been asking around in game and found out other players having had the same problem recently, though a very few.