Might be worth while asking ckolivas if the S3 binary he done to fix the stale shares filtering can also be used in the C1? I don't have a C1, but it might be compatible......
If S3 binaries run on the C1, my binary is compatible.
Are the S3 binaries still needed with the latest firmware? I'm getting ~4% rejected and ~1.5% stale on my S3's with p2pool