Do you play with a lot of topspin? Two things to try are to drop the tension like
@Soundbyte said above and see if that gives you more pocketing and grip for spin. Another approach is go to a thinner gauge poly for more bite but raise the tension to keep the power level down.
If you are already playing a thick, stiff poly and not getting the control you want, you don't have many things to try before I'd say go to a more control-oriented frame. You could go to a high tension and even more dead string, but you are really risking your arm health that way.