midi syncing two computers: works only one way

[lenartb]

i tried searching but didn't find anything that would help so far. here is my problem:
we're trying to sync two macbook pros, both running 10.7.4. osx.

when the computer A (master) is sending midi via m audio audiophile fw to the computer B (slave), which is receiving it through tc konnekt 8, everything works the way it should.

when we switch the cables and try to use the computer B as a master and computer A as a slave, it doesn't work very well. the tempo on the slave computer doesn't follow the tempo of the one on the master computer until the EXT button is clicked on/off one more more times (sometimes one on/off sequence is enough and sometimes it take multiple times). also the activated clips on the computer A wouldn't start even though arrangement position indicator is running normally.

we tried different MIDI port settings and it doesn't help.

when we tried switching the soundcards the problem remained the same. computer A (master, this time with tc konnekt was still able to send midi clock to the computer B (slave, m audio audiphile fw) and everything worked perfect. switching cables and trying to use computer B as master and computer A as slave gave as same bad results we got with the original soundcard setup.

thanks

[lenartb]

we finally found a cause to the problems we had;
computer A (the one that couldn't receive the tempo through midi sync) was used with electronic drum set, which would act as a midi controller for ableton live. the thing is this drum module has an internal midi clock which was sending midi time clock to the ableton live, therefore making ableton unable to receive that same information via midi sync with other computer. after turning midi clock off on the electronic drum set module, everthing now works the way it should.