First off, I cannot think of any technological reason as to how or why a CDRW disc could 'break' a working Xbox DVD drive.
That said, the last disc to be read on my Xbox was a CDRW drive (namely the "Ed's live linux .5" disc).
I have no idea if this is a coincidence, or just the fact that I bought my Xbox used (manufactured Nov 2001). I have no idea what life it this Xbox had before me. I used it for just over two weeks before it died. For the record, I installed a Bioxx in it shortly before it died (thankfully, otherwise I'd have not been able to do anything with it until I got the drive replaced).
No, I did not attempt any silly pot tweaks to make this happen.
Anyhow, I thought I would just add my $.02 to this, as no one else was able to come up with an actual case of this happening.