Hi, everyone! I've been a lurker for a while and this is my first posting. I'm over at the DAW-Mac list, as well. I already did a search on this site, but can't seem to find an answer. Perhaps someone here can help me. I installed PT 7 after a clean uninstall of PT 6.9.2. I am on a Mac Mini, OSX 10.4.3, with a MiniStack external HD, using an original MBox. I keep getting the error message (-9136): "CPA usage is holding off USB audio. Remove some plug-ins, delete some tracks, or increase the "H/W Buffer Size" in the Playback Engine dialog" everytime I record or playback. The problem is: I'm not using any plug-ins nor do I have anything that didn't come with PT's, I'm only working with 2 or 3 tracks (all spoken-word, no music beds) and the Buffer Size is already at the maximum. No matter what I do, including playing with the journaling/disabling journaling via Disk Utility - nothing works. I'm at my wit's end. What can I do to fix this??? This went on in my old computer, a Mac G4 Cube (running on OS 9), but not to this extent. Now I can't record or play back at all. I've tried recording to the internal drive (I realize it's a no-no), and even though that worked in the past as a temporary work-around, it doesn't help at all now. Any ideas? Thanks so much! hiho322