For chapter 5, they released a new client build, that starts at 5.x.x (can't remember exact). So you don't have to deal with all prior patches. It's much more stable. I was crashing several times per hour with the old client + 1 quadrillion patches. Now I crash maybe once every several hours with the new slim client. While this is purely anecdotal, others in my guild have experiences increased client stability with the new client. Might want to try it if you haven't yet.
Thanks, and where or how can i download, or re-download the new chap. 5 client? i have already played after it was released, and i did all the patches and updates, so how can i re-do that?