This is an occurence that happens with a very, very small number of Opti-PAC's for some reason. I have had correspondence with Andy regarding it, but we have not yet been able to determine what causes the Opti-PAC to lose the spinner connection. It is not the optic board on the spinner because I have had the opportunity to see this happen for myself. I put the suspect spinner on a different Opti-PAC and a Hagstrom ME4, and it worked fine. This ended up being very frustrating for one of my customers & myself because we kept sending optic boards back and forth. He would say it didn't work right, but when he sent it back to me it worked fine on my Opti-PAC's.
However, every occurence has been able to be resolved by connecting the spinner to the "Trackball" header, and the other control on the "Rotary" header. For some unknown reason, the spinner seems to actually like the "Trackball" header better. Try swapping your connections and see if that helps.