Notice that says scrypt with cgminer which does not apply to bitcoin. Eruptors don't have any way to set difficulty, they have extremely simple mining software built in that only does diff 1. You could probably use the stratum proxy by slush between the blades and your p2pool software to get rid of the message, but not sure if that really gains you anything but adds another layer ...
And this is a problem which has been solved long ago (p2pool is using the same protocol than other pools for quite some time).
I changed the FAQ entry and suggested using stratum-proxy when it becomes a problem (might help by distributing the load across CPU cores or handling share submissions more efficiently than p2pool).