https://bitcointalk.org/index.php?topic=158267.40Just read the thread on vpool, we are pretty sure it is a scam. If it's not a scam, it's very poorly put together.
Most of the shares you mine end up being called invalid by the pool, and the pool pays you jack crap for hours of mining. All of us running into this invalid share issue do not have issues with it on other pools. We are pretty sure the pool operator is really just skimming off the top of everyone's work (and skimming a lot at that), and just calling it invalid shares as an excuse to pay out so little.
Miner beware.