The issues with people having hidden GPU miners and getting enormous amounts for possible dumps to oblivion is also problematic.
I have same feelings that there might be private GPU mining XCN since day 1. I started solo mining Monero on 7th day and was able to find 4 blocks in 2 days with my computer running 8-core Xeon E5, but till now i have found nothing with XCN despite the fact that i have been solo mining it since first hour !
Private GPU miner is extremely harmful for the economy, XCN community should get a public GPU miner ASAP.