Yesterday I tried a CDR (EMTEC brand) on my CDROM2, but it refused to play at all...the lowest I can go on my writer is 10x
Lens is clean...gear lubed, gears run smoothly. And plays Originals....
I have the original brief case model setup as well, and it doesn't like CD-Rs much. I only bought that model because I thought it looked cool. For actually playing stuffs, I use my trusty SuperCDROM^2 unit. Plays everything under the sun.
As far as the Black Duo units getting the 'parked laser' issue, that's probably a bug in the firmware side of the CD setup. The laser module (on rails) goes too far to the right and the motor wedges it in there tight. It can't unwedge it though, so you have to rotate the spindle that module is on - manually. This only seemed to happen with really cheap CD-Rs, from my experience.
As for burning, the slowest speed doesn't always produce the best CD-R results for the PCe CD systems. I've have a burner that only produced working CD-Rs for the CD unit, if you burned at 16x or higher. If I burned at 8x (the lowest), they would hardly work on the PCECD units. Just goes to show, not all burners are equal; you need to experiment with different settings.