Got the R&B combo and im like a kid in a candy store, cant wait to use it. I just got it out of the box last night and I have a question.......When the grids slide in and out, are they still somehow supported? Do you have to hold the grid up to keep it from falling down? I thought it would be supported in some way but after my initial inspection, the best I can tell the grids slide freely and are not supported when they are slid out. Am I missing something?