Keef,
Could it be something as basic as CD+R versus CD-R?
This came up before -
there is no such thing as CD+R.
CD-ROM is a pre-pressed CD, CD-R is a write-once CD (WORM), and CD-RW is a re-writable CD.
The only variation on CD-R is between 74 / 80 minute (or 650 / 700MB) capacity. Yes, there are other capacities, but those are by far the most common.
It's only DVD that has the +/- business.
SD