Again this is while in cubase 4.5.2 using Omni I'm doing tons of browsing in and out of patches editing soundsources etc.. when creating a Multi. I had 4 sounds loaded up,finally I put in an arp for ch. 5 and out of the blue it just start's hummming... ?? weird .. lost the multi , oh well .guess thats my que for tonight..maybe auto save every 10 seconds?