Ok version.dat deleted, then i've run the updater, downloaded new files and patched client, alright. So I've logged in, but crashed at the loading zone screen after character selection, ("access violation... 6969CD0A" as before). Also there were some glitches at login screen.
Tryed a second time, now entered the game succesfully, but quests page is glitched as i said in the previous post.
Third time, entered game again, random glitches at login and quests page as usual.
So, now i've patched the game, but the issue causing instability is still not solved.
I'll try a clean install as Karyuu suggested.