BURNING ON MEDIA PLAYER 11

I RECENTLY INSTALLED MEDIA PLAYER 11 AND I HAVE BEEN ABLE TO BURN CD'S. FOR
SOME REASON, IT WON'T ALLOW ME TO ANYMORE. HERE'S WHAT IT DOES:

I CLICK AND DRAG THE SONGS I WANT

WHEN I INCERT A DISC THE PICTURE CHANGES TO: CD R , BUT UNDER THE "TIME
LEFT" BAR IT STILL SAYS: INCERT A DISC

WHEN I CLICK ON 'START BURN', IT EJECTS THE DISC AND TELLS ME TO PUT IN
ANOTHER ONE. MY DISCS ARE FROM THE SAME PACK I HAVE PREVIOUSLY USED TO BURN
DISCS. PLEASE HELP!!!!!!!