hello, i have a problem with midi timing in pure data.

i have an emagic unitor8 connected to an older dual cpu xp pc with a serial cable, this gives great midi timing with most sequencers. but with pure data i got bad results, note output is not consistent. even with a simple monophonic sequence :(
and it gets worse when moving the mouse or automating sliders (GUI activity)
i tried different asio/buffer settings, no improvement. it is an older machine but freshly formatted. Renoise and old Logic 5 run great on it and it has a 1Gb videocard (no graphical excuses)

running the same patch on a raspberry pi with an usb midisport 2x2 gives slightly better results. unfortunately the pi cannot run much more than this patch.

the same patch on my early 2011 SL macbook pro doesn't give great results either, both unitor and midisport usb.

i used this monophonic sequencer as test patch on all systems: http://blog.loomer.co.uk/2010/06/pure-data-midi-step-sequencer-2.html

is there a way to get better midi timing with Pd? i'm triggering 4-7 midi soundmodules without problem from other sequencers but Pd is having hard time with a mono-sequence...