If it's any help, I've noticed that the mining pools will only report your hash rate based upon the time it took for your client to find a share. I spent a lot of time and frustration figuring this out until I found a random post talking about it.

Example, I have 8 miners running a pool on Quark but only a few of them show up at a time as doing work since not all of them find a share at the same time. The server side estimate of your hash rate has nothing to do with what you're getting paid, its all about what you find.