I had exactly this problem this weekend when building some new machines. They have Asus A8N VM CSM motherboards in Antec Aria cases. The Aria has front panel memory card slots connected to an internal USB connector.
With the memory card slots connected, the Dapper live CD would hang at "Mounting root file system" I didn't play with boot: options - it was easier to just pull the memory card connector - with this done Dapper boots just fine. Note that the Asus BIOS does some kind of floppy/HD emulation with the USB devices, but I'm a big fuzzy regards exactly what. BIOS 1001 on the A8N if someone is looking to reproduce and fix this bug. It's pretty bad if the Live CD won't boot on such mainstream hardware. Ian -- Booting computer with attached USB-storages causes lockup https://launchpad.net/bugs/36508 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs