Hi Scotty,
Ages ago I posted the problem I was experiencing with my PSR640. During a song the music rack would pop out of its slot in the PSR's plastic casing (because the PSR casing would flex against the more rigid music stand). Very frustrating and veeeeery embarrassing. The only way I found to solve it was to keep an eye on it, because it would slowly work its way out, and push it back into the slot before disaster struck. Since I moved to the 9000PRO I don't have that problem anymore.
Jon.