Infrastructure Software

I recently tried to create the Enterprise-R5-U5-Server-i386-dvd dvd from the oracle distribution site.
1) i have downloaded this zip file : v20651-01.ZIP
2) extracted Enterprise-R5-U5-Server-i386-dvd.iso
3) executed this file with Roxio creator 10.1 so that it copy this iso file to DVD
4) after the copy, a verification check is done and the dvd's content is ok

5) insert this DVD into my pc and boot from dvd

6) do the dvd The dvd execute and displays 2 nbutton : test and skip
test button is to check if the dvd is ok

but i always have this error :
" the medium check failed for the image ENTERPRISE LINUX 5.5 "

I've tried at least 5 times , burned 5 DVDs and i've always have this same error.
I've tried also to re-download the zip file and tried again , and always the same error with this new zip file.

Does somebody tried to download this same package and got no error with the test?
or ddid somebody got this same error and if so, what can i do ?
Is this really an error or can we ignire it ?