John Doe,
Someone told me of a method of saving log files from the installer before
it writes to the hard drive it's going to install to.
The error occurs prior to writing to any partition.
If these errors are kept in system RAM until the partitions are formatted
and then written to that partition, all is OK,
But the errors precede writing to disk.
I've asked already, maybe you answered with your "debug d-i" comment but I
have no idea what it means or how to use it to help the boot and installer
developers.