Don't know what burnproof is...
With the old CD-Writers (like yours), once the laser fires up to burn the pits in your CD, there's no turning back. This means that the drive's internal buffers
must have data to write
at all times, otherwise, you'll get a coaster since the laser is going to burn through the CD whether there is valid data or not. This is why burning CD's on drives like yours is super CPU usage sensitive. If your PC is busy doing other stuff, it may not be able to keep up with the drive's need for data.
With the introduction of BurnProof technology, this is no longer true. The laser can be turned on and off (figuratively) at will, so if there is no data, the drive simply waits until there is some.
Anyway, when burning a CD in MC, 1.) make sure there are no other tasks/applications running, and 2.) make sure the files are local and not on a network. If this is already true, then your best bet is just to upgrade to newer drive since maybe MC is just not fast enough on your system to keep up for some reason. (These days, they are practically giving them away anyway.)