Incorrect Product Total

I have some selects for my products.

Option one selected (for example) is £0.06
Option two selected (for example) is £0.06

The total generated is £0.13

Any one any idea what is going on?

Thanks

They display only 2 decimals when its listing the option price, but when they get summed up for total what is after those 2 decimals also get counted and then the result gets rounded to 2 decimals. So thats why sometimes there is that difference.

Ahh..ok thanks