Please help support the site by donating at the link below.https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=8ZRU34U47BESW
Could also be a dust/lint build up on the rubber pad, circling the spindle, which grabs the disc. When that gets dirty, it lets the disc slip on the spindle, resulting in a "screaching" sound.