Heya Chud, what's up?
There were 3 dungeons in the 1st act as you already know, and there's 6 dungeons in each of the last 3 acts. Also, as far as I know, no one's been able to find the battlefield key for the 6th dungeon in act 4(including me). So I never was able to get access to it.
You're still in act 2? Family life getting in the way of gaming? D'oh! Better you than me, eh? <img src="/ubbthreads/images/graemlins/winkwink.gif" alt="" />
Later dude