OK! I'm in disbelief! I've just spoke with Apple Logic Support, and it seems that all these "out of Memory" messages we get are "normal". Man, I have 5 frozen audio Instruments tracks and only 2 open Plug-ins. I must admit I also have 35 audio tracks, but would that use all my 4 GB RAM? Is my situation normal? Apple tells me that L9 takes more memory and it would be just the same if I had the most Powerful Mac Pro. L9 itself cannot use more than 4GB total. Are you guys experimenting similar problems? Is my situation normal? Thanks for your help! Andre Favreau They also tell me that to use more RAM, it is possible to use the standalone version of plug-ins with SoundFlower to route the Audio and the IAC driver to route the MIDI flow.