The normalization is configured on the NORMALIZATION page which shows the averaged PET image.
The configuration of the Template Based Normalization is crucial. PET (SPM5) is the default selection and refers to the perfusion-weighted PET template provided with SPM5. Please refer to the section above for more information about the Diffeomorphic Matching (ANTS), User Defined Transformation, PET template and User Defined templates.
The spatial normalization is started with the Normalize action button.