As far as I can tell the ccminer does validate (checking if the result can be considered good) the share before submitting.

CCminer shows "yayy!" or "boo!". If I enter wrong settings or overclock hard the miner shows "result does not validate on CPU" or something like that, so I assume I submit only valid shares. Most of them should also reach the pool, because I got several AMD based cards running on your pool too and the hasrate and payout fits just perfect. (at the same location and connection)

On ccminer however there is always a 20% cut in hashrate displayed and payment received.

I watched some posts from tsiv here. Tsiv, if you read this, maybe you have further help or ideas where to look.
Or anyone else using tsivs miner, since it is the only one for monero and Nvidia cards right now.