new itunes problem?

[nichless]

Maybe someone out there can help me.  I installed the latest version of itunes on my macbook and now--for some unholy reason--I can't burn discs anymore.  It goes through the process, but after it's finished I get a "medium write" error message.  The disc plays fine for the first 5-7 songs, then there's nothing.  The track names show up, but there's no music there.  

Is anyone else having this issue?
Any ideas as to what might be wrong?