Often times with WoW, people have crashes due to mods. Usually out of date mods. I'd recommend to start updating your mods and if that doesn't work, disable all your mods, and slowly restore them until you have a problem. Lastly try deleting your wtf folder (save it first, so you can restore if it doesn't fix your problem). Most friends who have had problems with WoW found this will usually fix it for them.