I have set up my products so that their price is inclusive of Tax.
However when I get to the Checkout page, the tax is being added to the Product Price. Where really it should only be there as a summary.
Anyone know how to fix this?
You need to have the correct settings in your configuration.
Look under System/Configuration/Sales/Tax/Calculation
There are two important choices here
These should both be set to the same value.
If you write your product prices including taxes, then these options should be set to yes.