A study of heavy N=Z nuclei including t=1, t_z=\pm 1 pairing only clearly reveals the shortcoming of that model in T_z=0 nuclei. We present a simple model in which we study the response of isoscalar t=0 and isovector t=1 pairing correlations to rotational motion. In particular, we address the role played by the t=1 and t=0 pair gaps with respect to the band crossing frequency. We argue that the t=1 neutron-proton pair field is of limited importance in even-even nuclei. For the t=0 pair field, we introduce two different pairing modes. One is invariant with respect to signature symmetry and one is not. The signature conserving mode results in a delay of the band crossing frequency, whereas the signature breaking part enhances the rigidity of the moment of inertia.

PACS numbers: 21.60.--n, 21.10.--k, 74.20.--z