You can take the Ubuntu install disk out of the equation and go directly to the Ubuntu repository for b43-fwcutter. Look at your /etc/apt/sources.list. At the top of the file, there is an entry telling apt to search the install cd, followed by a listing of apt repositories. As root, edit that file by adding a # at the beginning of that line to comment out that line. Apt will then ignore it and go to the repositories looking for fw-cutter.
sudo apt-get update
sudo apt-get install b43-cutter
should then work to install the package.
2. The command works for a while, then responds by asking me put the disc labelled " Ubuntu 10.10_Maverick Meerkat_ - Release i386 (20101007)" into the CD-ROM drive and press ENTER.
The label isn't the name of the disk; it's in a file in the .iso. When you put the disk in the drive, apt will attempt to open and decompress the .iso and look for the file which contains the label information. Renaming the file won't work. Downloading and burning another cd might work. But, as I explain above, it isn't necessary. It's just convenient to be able to install from the cd instead of over the internet.