Dude, so much AD here, why not clean them all?

Hello.Medium not present - I have had great sucess ripping and burning dvd's until last week. Now whatever I try I am getting a medium not present message. So I thought it might be my burner so I went out and bought a new one but I am still getting this note. It doesn't matter which program I try to rip with, it's saying I don't have a disc in the drive. And yes, I can play the movie with windows media, so I know it is there. Help please. Maybe a clue here, but not sure. I d/l a ripper last week that said it was in conflict with another one and did I want to uninstall that one, I did, but this seems to be the start of the problems. Unfortunatley I don't remember the programs tho...