Hello and a question (p2pool)

Hey, been lurking for a few months, didn't realize there was an initiation phase on the forum. Understandable when dealing with money. Anyway, hello everyone, enjoying my mining so far (as much as you can enjoy scrolling white text).

I've been running with p2pool for a while, and get about 620Mh/s on a 7950. I can't run it perpetually because its on my only computer, but when I'm in classes or at work I leave it going, so usually about 10 hours a day. I usually end up with about 5-10 shares with only 0 or 1 stales. I recently messed with my router to open up some ports to help with latency (DSL ftw), but now I'm only getting 1 or 2 shares a day, with a very high stale rate (50-100%). Opening the ports has increased my incoming connections from 0 to 5-6, and my hash reported by p2pool has come more in line with what cgMiner shows, but I've gone from about 0.03 payout for the last couple weeks down to 0.005 ish. According to p2pool, it should be about 1 share every 1.9 hours. I realize there's a lot of luck involved and this isn't an absolute number, but this just seem a bit too whacky for 3 days in a row.

Is this just statistics being a jerk or did I screw something up when I forwarded my ports? No other changes except increasing work size to 256 from 64 (This should have no effect). I checked my ports with yougetsignal.com and they're coming back green now, so I'm doing that right afaik. All other values (hash, acceptance rate, etc.) are reporting exactly the same as before.

If it helps:
7950 OC: 1206/1575 Mhz @ 1.26V with AfterBurner
Pool: p2pool 11.4
BitcoinQT 0.8.2
Miner: cgMiner 3.2.1
Custom cgminer configs: workload 256, intensity 9 (~2% reject rate, 0 errors), all else is default.
W7 x64
Phenom II 720 BE (oc/unlocked core)
8gb system ram
3gb gpu ram

I know it was all set up correcty because I've been running for about a month and have been payed out successfully until this all started. I've googled and browsed the p2pool thread (can't post there yet, just registered), but haven't been able to pull anything up.

edit: just wanted to add that p2pool.info reports me hashing at ~150Mh/s, and it's my understanding that it's calculated by the number of valid shares submit per time period. It used to report me at ~600Mh/s. While typing now, cgMiner says [(5s) 625 (avg) 632], p2pool client says [Local: 715MH/s] (it spikes like that sometimes. Ever since I adjusted work size in cgminer its been pretty spot on). If this question could make its way to the p2pool thread, that'd be great, but don't break any rules if it's not allowed.