Sometimes my blu-ray player will "freeze up" after a few minutes when playing a Blu-ray Disc, but not all the time. It only happens after I've played a DVD disc! The player will not respond to remote control or front panel buttons, I have to remove / reinsert the power cord ("cold boot" it, I guess), then it will play the entire Blu-ray Disc no problem. I installed a 8 gb thumb drive in the rear usb slot, I will experiment to see if problem happens without the thumb drive, or if using a higher capacity drive helps. It's a Yamaha BD-S477 (no longer manufactured).