Cd-rw reads full when it isn't

I use the xp built in software for copying data files onto a cd-rw disc. It will work for awhile but then all of a sudden when I try to copy over some more files the cd-rw disc reads full. I only have around 60 mb’s on the disc so why would it read that it’s full? I have to erase the disc in order to add more data files onto it. Does anyone know what could be causing this to happen?

When you say it will work for a while do you mean that you can copy stuff repeatedly on to it before it stops working; or what?

I can copy files say 10 different times but then the 11th time it tells me the disc is full which isn’t true.

What file system is being used on the disc?

CDFS

what does that stand for?

What don’t you use real burning apps?