In http://ubuntuforums.org/showthread.php?t=1867927 I've serached for solution for my problem with boot and delays due to DVD timeout.
I've found a solution, for example here it is nicely explained... http://paulphilippov.blogspot.co.uk/2011/07/how-to-fix-slow-boot-with-ata-errors.html
Thank You Paul!