Next difficulty retarget occurs at block 526175.0 (eta 10.8 days): 5.17423501215e+12 / +20.1% [est.]
Wtf? 20% increase?
Which means 20% less profits.
I think the last diff increase was just yesterday, might have been a bunch of quick lucky blocks or something.
Wait a few days and you'll see it level out a bit, as the network hashrate doesn't appear to have jumped drastically.
On the other hand a 20% increase is not unheard of there have been a few of those since I started mining last year.