when I first starting playing DEEP stack hold em, I got creamed and couldn't figure out what was going on, I was playing the same successful game as 100bb stacks.
The implied odds of playing connectors and even junk is huge if the guy you are playing will overplay his "big pair". That's what I did (overplayed) and they gutted me regularly with 84o and J2s.
You definitely have to loosen up and play late position more in deep games. I find it much more difficult than 100bb buy ins, I am still working on it.
*EDIT* I thought about this more last night after I posted. When playing deep, your raises and bets have to be bigger to take aware their implied odds, basically a Donkey Tax for chasing. This was the mistake I was making when I played deep NLHE, all my bet sizing was correct for a 100bb game, but insufficient for Deep Play. Their implied odds if they hit were great.
JC