The only time I remember any stability (pricewise) at all was when bitcoinica and then later maybe pirate stabilized the price..
Stabilized?
Well, Bitcoinica blowing money toward conservative speculators may have stabilized against short-term volatility. But generally, leverage mania wasn't much help for stability. Remember the spike below 2 USD? Bitcoinica. Remember the flash crash? Bitcoinica. Remember the spike up right afterward? Bitcoinica. Their users were leveraged way over their head for extended periods of time, I remember it all too well how one had to use Bitcoinica's hedging balance to estimate actual liquidity.
Not going to comment on Pirate.
The time of stability this spring was after a lot of maniac speculators had been burnt, and most Bitcoiners had sane expectations about price. There just weren't many people speculating on "To the moon tomorrow" or "ZOMG crash". Also, wild movements transfer money to those who stabilize. Thus, the extreme swings before might also have helped.