[maxmsp] Max weird unresponsiveness

I am using Max/MSP 4.6.3 on OS 10.5 Leopard, with a monome interface (www.monome.org), specifically with a sample-cutting step sequencer patch called mlr (I would attach the patch but it is really dense and would take up 20 pages - you can access it at http://monome.org/data/app, but it won't do you much good without the interface.)

I've been posting on the monome forum about this but so far no one has been able to find the source of my problem, so I thought I'd bring it here.

mlr sends and recieves osc data from MonomeSerial - an app that interprets the monome's serial data and converts it to OSC or MIDI.  mlr is recieving OSC from the interface, but it only responds to it under strange circumstances.

For instance, when I push the button on the monome that is intended to make the sample begin playing, nothing happens.  But if I go into DSP status and change any of the pop-up windows (i.e. change internal mic to line in, or change the sampling rate... change anything) I will hear a pop and the sample will suddenly start playing.  Another instance of this is when I trigger it to play while in max nothing happens, but if I then toggle active applications (i.e. switch to Firefox) it will suddenly start.  This is not just the case with triggering it to play, it happens with almost every function in the patch.

I know for a fact that there is nothing wrong with mlr, because it is very widely distributed and as far as I can tell no one else has had any problems with it.

I'm running it on a brand new Macbook Pro with Leopard, and I re-installed Max about 4 days ago. I originally transferred my Cycling '74 folder from my old macbook pro, but out of fear that that might be causing the problem I wiped it off and did a clean install.  

I should also mention that I tried running it on my old macbook pro, which is overloaded and corrupted and about to explode, and mlr worked just fine.  That made me think this could be a problem with Leopard compatability (but as far as I know no other monome user has had Leopard issues).  Anyway, that's about the extent of it.  If you need any other info let me know.

Any suggestions?

Any help is greatly appreciated.  Thanks a bundle,

--Meade