Something is very weird, or at least I don't understand it:

ROI block explorer shows network hashrate: 290.6160 KH/s (current block 79777)

1. Suprnova pool: 285,859.434 KH/s (current block 79777)
2. Optiminer pool: 26180.1h/s (current block 79778)
3. Coinspool PoolL 5 kH/s (current block 79778) (yes there are still some people there)

Three pools together make approximately 316 KH/s while block explorer is on 290 KH/S !?
What about solo miners, they add some mining power too??

Network hashrate is not reflecting agregated hashrates across pools and wallet miners.