Rrsp optimiser shows an amount but it should be zero. I have clicked all the right buttons but optimiser is stubborn, how can I change it?

The optimizer is only a suggestion. It does not change your return figures. 

Could you please tell me what section is supposed to have a balance of $0.00?

The contribution is calculated from what you have entered on the the previous RRSP contributions page. You can use the slider to change the contributions to recalculate the possible balance, but the current balance is calculated from what you entered previously.