I solved my Age of Conan crash problems by following the advice of a friend and guild mate, who insisted that I buy a sound card, because that would make my computer faster than just using onboard sound. I'm not an expert, but it appears as if my Nvidia motherboard doesn't really have a sound chip, it only emulates one using CPU power. So adding a sound card would free the CPU to do other stuff. I found a Soundblaster Audigy SE for 40 Euro, installed it, and tested that my AoC crash problem when casting a certain spell with sound on was gone.
But that was all I did in AoC last night, because then the European servers had a server maintenance downtime for 8 pm to 1 am scheduled, in preparation for the Euro launch on the 23rd. I really don't understand why all this downtime always has to be scheduled during prime time. And I've read the US early access period was even worse, because it was only 3 days, and of that time the servers were up only 48 hours, with one downtime scheduled the evening of the last day. I so hope that once the game is launched everywhere, the maintenance window is moved to mornings, local time. I find scheduled server maintenance starting at in the evening or late afternoon unacceptable for a MMO.