I'm having a strange problem. Since Audio effects can't receive midi and I need both audio and midi-in in my patch, I've made a separate (midi)device which sends midi information from a midi track to the main device (located on an audio track) through udp. I've used it for some time now without any problems, but the other day I tried to change the sample rate in Live and suddenly the main device (audio) stopped getting midi from the midi sender device. After debugging for my self and searching the forum I still can't find a solution for this. I've read this thread (http://cycling74.com/forums/topic.php?id=23224)
and I suspect this might have something to do with the asynchronous issues, but I'm not sure.
I found out during debugging that everything always gets back to normal when I change the sample rate back to 44100 and if I leave Live alone for a couple of minutes or so, it seems like the connection is restored and midi is flowing through. Also, if I have the main patch in edit-mode, everything works fine when I change the sample rate. Lastly, I tried to send midi with send/receive-objects instead and they have no problem with the sample rate changing. I guess I could use this solution instead, but I vaguely recall that there were some other issues with send/receive which lead me to use udp instead.