iTunes won't burn playlist under 80 min/700MB?

Hi everyone,

I'm trying to burn a playlist of French music for a project. The playlist totals 54 minutes in length and 58 MB (all files are mp3s). I've tried using two different brands of CD-R discs which each claim to hold 80 minutes/700 MB but to no avail. I figure this is a problem with iTunes but can't begin to think of how I might resolve it. I've had no issues with iTunes burning up until now. I've checked for software updates and there are none.