Ubuntu 7.04 Feisty Fawn on Parallels - CD-ROM Detect Error
— Paul Annesley, April 2007
UPDATE: Solaris CDROM emulation does the trick for Desktop Ubuntu. For Ubuntu Server, read Ubuntu 7.04 Feisty Server & Parallels - CDROM/Kernel Workaround.
If you're trying to install Ubuntu 7.04 Feisty Fawn on Parallels Desktop for Mac, and getting an error like "No common CD-Rom drive was detected", this might save you some further googling.
Apparently an issue introduced in some configurations of linux kernel 2.6.20 causes the Parallels emulated CD-ROM to not be detected.
A workaround I found at the Parallels forums suggests changing your virtual machine type from "Linux" to "Solaris" during installation. This certainly got me past the CD-ROM detection error, and got Ubuntu server fully installed.
Now... if only it would boot.
EDIT: No luck with Parallels - I'm giving it a shot in VMware Fusion Beta. Looks good so far...