Vnpenguin,

"No, there is another error in which we see explicitely "command not
found /usr/bin/eject" ..."

The path to the eject command on your system is incorrect. I noticed these problems when I was building my first few live cd's.
You should be able to modify the mayflower script to /usr/sbin/eject instead of /usr/bin/eject (note the 'sbin'). It's a path
related issue. As a normal user when you issue 'which eject' it should show /usr/bin/eject, but as root it will show '/usr/sbin/eject'.
Odd eh? But that fixed it for me...

-Adam