If you have a low hashrate payouts aren't constant, you sometimes get more, sometimes nothing, takes a while to start getting paid, that's why people leave: they stay for half an hour without paying any attention to tweaking their cgminer config if needed, they see they don't get paid and they leave. You also may have to tweak some settings to avoid dead shares.

Have a look at CrunchPool: http://crunchpool.mooo.com/ we have a tips&faq in our p2pool nodes to help you get started.