I guess that will change when the blocks halve, is there a countdown location were I can see that?
You can see current block number on the "game" tab. Reward halves every 1000000 blocks.
I had most of last nights mining rejected for some reason. There was a long list of coins mined but rejected with a -1 of 6 (i think) error.
1) Try to sync your system time.
If it doesn't help then:
2) Are you behind NAT? Try to setup port forwarding then.