Read an article yesterday, I think it was in the WSJ, about how banks are reluctant to go above the $10B mark that would trigger the extra rules and fees. Said some were managing deposits to stay below while they could.
Another possibility is B of A just announced they are no longer doing business with Fanne Mae. Some banks are much more carefull about who they would make a house loan to because of the buy back provisions.
Just a couple things that may have influenced them... I don't really have any idea why