i'm having some issues synchronizing an Electrix Repeater (slave) with Live (master). the two never quite seem to lock in, though it's better at faster tempos. it's always a fraction of a second off, and the tempo seems to wander, sometimes better, sometimes worse.
i've tried adjusting the latency in midi sync section, and a negative figure seems to work better (resulting in "0 latency"), but still not good enough for my rhythmically-sensitive drummer.
i know this isn't a general problem with midi, since the repeater syncs with other gear without issues (though its display wanders a bit). one thing we're considering is getting a midi-thru box and slaving everything to a drum machine.
Please see my previous posting (http://www.ableton.com/forum/viewtopic.php?t=3683) for a complete hardware/software system description.
thanks!