Actually I have noticed this too.. mostly with high difficulty coins like NVC and LTC.. you can mine for 30 minutes.. then not go back and within 1 hour your mined shares are absorbed into long waits between finding blocks. So what happens is your 30 minutes of mining is gone and gives back nothing.. this happens more than it should as LTC and NVC can go a day without finding a block. There is no way to avoid this and it becomes a loss on a regular basis.
if we mine ltc and then switch to another coin without finding a block, will the shares count or are they gone after a while?
they "count" but the shares go away after a short while. I think this is a major problem with the pool.
Flound I thought you said minimum 10 mins on each coin eveyr time there is a switch. I swear it switches more than that.