That's tough to take, but probably bad luck. What are your node stats? I have nothing close to your HR, but I have gone two days @ 1.1 TH/s without a share recently. Bad luck and then from the 16th to 17th did 8-9 days of mining on P2pool. The best day. It made up for it all.
You running on windows on linux?
Got any screen output? Any P2Pool errors?
I have been having some Bitcoind crashing issues lately. I'm trying to work on those now. Pretty sure it's memory related. I hope.
Mining for 13 hours at 5.2TH/s, expected time to share 2.0hrs....
Actual share obtained so far: 1 total (1 ophaned, 0 good) ......
Pure bad luck or setup issue???

Seriously, should have got 6 shares under the "expected" scenario.