Briefly, this was my original problem When trying to write (latch, touch or write) automation via the mackie control, the logic timeline begins to visualy slow down. The more faders i use the more it slows down visualy and starts showing the 'busy-clock'-symbol. When using the faders more, eventually audioglitches start to appear. When proceeding to try to further write automation, logic stops playback and needs a minute or so to recover. My actions so far. Having my doubts about the midi interfacing on my fireface 800, audio having priority over midi and firewire-bus on my mac maybe not able to cope with the data-stream? I was thinkingh to try out a seperate midi I/O, some others on the forum also had midi problems with similar gear. (motu firewire 828 if i'm not mistaken) So, they also suggested to try a usb I/O-box. Yesterday I went out and bought a Edirol UM-2EX, at home installed the driver and gave it a try. Sad to report that it didn't make any difference. (again also tried it with my laptop an also the same result) Maybe i'm just ecspecting to much of writing automation of a few channels at the same time. When testing i'm actually trying to write automation of 8 channels at the same time (just volume parameter). Not very likely that i will ever write automation of 8 channels at the same time, but why have 9 faders on it then. So maybe somebody else can tell me if i'm overstressing the system, or is somebody able to perform this without the sreen-update slow down???? My setup is; Mac G4 dual 867MHz with 1 GB ram Fireface800 connected via RME supplied firewire400 lead (restricted to use analog I/O and spdif only, saving on firewire bandwith) Mackie Control (firmware v2.1.2) connected to the Fireface 800 midi-ports Logic Pro 7.3 Powerbook 1.67 GHz 1 GB ram (not part of the setup, but tested fireface Edirol UM-2EX (not in use, anymore, midi no connected via my fireface as original setup was) greets Marius