thats weird, i always just opened an external midi track and it worked fine, i havent done this for awhile, ill try it today if i get a firewire cable, i cant connect my soundcard right now cause i dont have one; i need to get on that.
some of my directions might have been wrong cause i was going from memory, so sorry about that.
you shouldnt be hearing a loud squeek though, there may be a feedback loop somewhere.
the transport should be sending though mmc, if it even sends at all that is.
why dont you just use the transport in logic by clicking with your mouse? i never used the transport in my mpc when using logic as the sequencer.
if you want to use a physical transport control instead of relying on your mouse,check this thing out
http://www.sweetwater.com/store/detail/nanoKON2bk/or this
http://www.sweetwater.com/store/detail/FaderPort/i would be willing to bet that the faderport has better build quality, those things look dope!
also, on my logic key commands, i have set up the [ and ] brackets set to jump ahead a bar and behind a bar, that might help you out too.