faulty CDROMs

[gbburkhardt at verizon.net (gbburkhardt at verizon.net)]

I've been having trouble with burning CDROMs; every so
often, I can't read a file from a CDROM I've created.
This is especially annoying when working with an ISO
image from a distribution.

Does anyone have any general rules of thumb on how to increase
the yield?

And, second, is there an easy way of getting an MD5SUM from
a CD that I've burned?  All the ISO images I get have MD5SUMs
from the distributor, but the only way I've found to check
them is to mount the ISO image with the loopback device, and
use "diff -r".

Thanks.