Trying (and failing) to use pitch tracking to play LoopShifter

Maybe someone can help me understand what's going on. I'm trying to convert pitch and amplitude output from [fzero~] to midi information I can use in LoopShifter. I think I have it mostly worked out except that it only (sometimes) works when I've got LoopShifter in an edit window. Never when it's loaded just as a device. Also, even though my patch always hears and sends the data in the way I expect, LoopShifter doesn't always play back my sample. I even hooked up a couple [number] boxes to the output of the "Display MIDI Notes" [kslider] and the pitch/velocity match across the board, but still - nothing. Any thoughts? - Adam