Hey guys and gals, Just wanted to get your opinion on something. A couple of weeks ago, there was a vibrating sound coming from my rig (turned out that one of the pull-out light bars on my Rack Rider had pulled out a touch.) Anyway, before we figured out what it was, the guitar player was saying that I really ought to have a square piece of foam between my rack and my top cabinet. He said the vibrations from the cabs are eventually gonna shake something loose inside my amp. I checked the rack screws on my amp and Rack Rider and they're all tight as a drum. Didn't look inside the amp. Does anyone do this -- put a buffer, such as a piece of foam, between your amp/rack and cabinets? Are they any pros or cons? Guitar boy gave me the foam but I haven't "installed" it yet and don't really intend to, unless someone gives me a compelling reason. Thanks!