Why are X11 payouts consistently below DASH?

Been watching this on the 1 MH/s expected payouts chart for a while now and it seems to be the exception that PH is higher than DASH. Why is the pool under performing?

The DASH client is buggy and crashes continually, making it impossible to mine DASH 100% of the time. The expected payout for DASH assumes that it is possible to mine the coin all the time, which isn't the case for DASH.

Chris is working with the DASH developers to identify the issue. If they can't figure it out, then we'll reduce that figure by whatever the crash rate of DASH is so that the chart is more accurate.

Thanks