I have another thread where I was seeking some help with my AES cards. I have some surely odd behavior going on. If I assign a channel to bus 17 and the channel is open and unmuted with the fader up at all it will send a harsh digital noise to the output assigned on my AES card that then shows up in pro tools. If I assign a channel to 17 thru 24 simultaneously all of them work perfectly and show up as expected in pro tools. Other partial combinations also work but other bus outputs in the 17-24 range will have digital noise. I cannot figure it out. It appears to be more tied to the card slot than individual cards. My two AES cards in slots 1 and 2 work fine. For a long time I had the firewire card in slot 3 and it worked just fine. I think at one point I might have had two AES cards in 3 and 4 with the FW card in slot 1 but I don't remember. I am dumbfounded on how it works in some ways and not others. I've been using DM boards since the 24 and I also have a 3200. I have never been so confused. The service manuals don't really get into the expansion cards so it's kind of hard to know if there's anything I could learn from that.