I've tried the manual deletion as well...in fact the manual deletion doesn't work...using that method, when you open launchbox again the playlists are still there.
As far as adding ROMs I drag and drop from my ROMs folder to trigger the launchbox wizard, I go through all the steps, and then when I click finish it shows at the bottom of launchbox the working progress bar...and at the very end it will show "creating playlists"...then it finishes and my ROM is added...I don't want these lists to be created