Cain2 Mining – IMPORTANT
The RTT target (Real-Time Targeting ) starts low (difficulty high) and increases (decreases) during the block, depending the timestamp of the block being mined. Therefore, miners running standard software may experience rejected submissions until a certain point (407 seconds). Worse, after that, they may fail to submit a block that is valid.
Slight (and hacky) modifications to ckpool allow it to mine chain2 in a reasonable way with no stratum client modifications needed: See https://bitbucket.org/
The incentives established by this algorithm do not favor inaccurate timestamps, therefore using the timestamp as a nonce is not attractive.