Yeppers, try ripping them to WAV files on the hard disk, and use CD Creator or whatever to burn from hard disk to verify this.
But MOST of the time, espeically on generic CDROM drives, DAE speed is nowhere near the X rating of the drive itself, especially for the beginning of the media compared to the end. Unless you have a high-quality CD Drive known to have very good DAE speeds, 12x burn needs data faster than the CDROM can give it.