Can you clarify what they are doing that is incompatible?  Is it just that they don't actually verify a share against the given target?  I "fixed" that by modifying my proxy to check a submitted share against the target and silently drop them when they are not valid so that p2pool never sees them.

I only care because DiabloMiner now uses a kernel that is not compatible with my GPU on OS X (basically, any phatk-like kernel fails and only a poclbm-like kernel works).