Don't use the mining proxy? iirc p2pool works fine with getwork.
ASICMiner Block Erupter Cube directed to p2pool has only about 60% efficiency
and p2pool not show hashrate fo it insted console msg:
I believe others have said cubes don't work well with p2pool. But hey, 60% is better than 0% with the proxy.

Seriously, I suggest another pool with a cube.
cubes work well with proxy - 97-98% efficiency...
will be fine that proxy work with p2pool...