Install problems on Performa 6400

[wataru]

Hello.

I had YDL2.1 installed on my Performa 6400, and wiped it
to install YDL2.2.  But I've been having a problem:
During the package installation, it will hang about 2/3 of
the way through the "Transferring packages" part.  An error
dialog comes up and says "Error:  Errors running transaction
set!  Please correct this manually."  I click ok and get a
new dialog:  "Package install failed."

This happens whether I do the custom or default installation,
and whether I use the 2.4 or 2.2 kernel.  I downloaded the iso
twice to make sure it wasn't corrupt, and the second time I
made sure to burn it at a low speed (4x; I did the other at 24x)
but it still doesn't work.

Any ideas?

Thanks,
wataru