My poolside hash rate look fairly close to my local reported rate. I've got two asic rigs, one is based on DualMiners and the other on Gridseed 5 chip units.

If you have multiple pools in your config, maybe some of the hash is pointing at another pool? I see a small amount of leakage to my second configured pool every day. I assume that there are occasional connection problems to WP, so hash gets briefly redirected. But my config is such that it always returns to the primary pool.

Do you have logs that you can check? I run cgminer as a service under Daemon Tools, so I always have a rotating log that I can check when stuff goes weird.