Easy Cd Creator 5, Win 2k, and Win XP

I use a computer that has windows 2000 and easy cd creator 5. when i burn files onto a cd-r with the win2k computer and put in in a win xp computer it reads it 90% of the time. now when i burn files to a cd-rw and put it in the win xp computer it wont copy files off or won’t read it at all. what gives?