Installation problems on Sony Vaio PCG-N505VE

[pwp7669]

SCENARIO:
- This model of Vaio uses a CD drive attached via a PCI card --- some proprietary Sony technology used to interface with a
6.5 Gb Toshiba ATA Hard Drive
- The only BIOS boot choices are CD, Floppy, and Hard Drive, currently prioritized in that order (Note: no USB)
- Wireless/wired network connections can only be made via PCI cards
- Installed RAM is 128 Mb, the maximum for this machine
- Xubuntu 10.04 is currently installed on the system, and <mostly> functional except for wireless network access and a few
other problems.
- My goal is to replace Xubuntu with Lubuntu.

PROBLEM SYMPTOMS:
- With the Lubuntu Live CD disc installed in the CD drive, I boot the system
- The Lubuntu language screen comes up; I select English, and hit Enter
- The Ubuntu 10.10 screen comes up, complete with four progress dots (. . . and .)
- The computer's Disk Busy light blinks intermittently for a minute or two and then the following msgs appear:
BusyBox V1.15.3 (Ubuntu 1.1.1.3-lubuntu 5 .......
(initramfs) Unable to find a medium containing a live file system.

MY GUESS
- The non-standard PCI-connected Hard Drive is confusing the Lubuntu install process, causing it to look for a live file system on the hard drive rather than on the CD

Any suggestions?

[pwp7669]

One more tidbit --- the Floppy on this machine is attached via a USB interface, so it is an either/or with a USB stick since there is only a single USB port available.
The big attraction of this laptop is that its amazingly light --- under 3 pounds --- but the drawback is that all I/O but the internal hard drive is some sort of add-on.