i own an eps16+ rack and can select wavesamples via midi(though sometimes i wish it could be turned off). i use os 1.3 which i believe to be the latest, my only guess is it's midi related, maybe try hooking up only your controller to the eps loading an instrument into say track one and testing this out to see if it works, if so keep adding your midi gear and connections till you finally hit a point where it won't work....troubleshoot.