|If the cdrom works OK otherwise then I doubt it a loose connection.|
You might try hitting the pause/break key after you start it up but before the OS starts to load. Then see if the cdrom still does it. If so it must be the cdrom. Even if it doesn't do it then it might still be a cdrom thing. If you can swap it with another that would let you know for sure.
Real men don't use AntiVirus; they just reformat