technical question

I've been using Windows Media Player for quite awhile to make CDs (mixes of stuff that I have actually bought, yes), and it's suddenly acting odd. I put all the CDs into a list, like I always did, hit the Copy CD button, and then it coverts them but won't burn them - just ejects the thing and says the last track is complete, but has a ! in red, which is the signal for an error message... I don't know why it's doing this, and I really wanted to burn my favorite IG songs on to a CD to take on my road trip home tomorrow. Any ideas? I did just add MusicMatch to my computer - could they be conflicting?