sounds similar to my guild's yogg attempts.
we cruise through p1, then p2 hits and sometimes we get can get the brain down in 3, sometimes it takes 4, but we are often overwhelmed by the tentacles up top.
I know this fight heavily depends upon quality decursing in p2 and good dps always.
Its also a tough fight because of the portals - someone takes the wrong portal and it can throw off a bunch of stuff, or if someone doesn't make it to a portal due to being grabbed, etc.
We've been stuck on yogg since May btw.. Summer has been rough for us with people quitting, leaving the guild, etc.