problems booting knoppix 5.1 & about knoppix's updates

Hello to everyone.
I am rather new in linux systems. I have just started my new knoppix 5.1 dvd and i have received the following message - insmod: 'can't read /cdrom/knoppix/modules/cloop.ko'. also just before that on the screen i can see the following - accessing knoppix dvd on dev/hdb... and then THE MESSAGE. Please help me to solve that problem. I have tried to boot with - knoppix ide2=0x180 nopcmcia, but it did not work.
And another question - i saw on www.knoppix.de available update to knoppix 5.1.1. Is it possible to update knoppix and how if it is yes?
Thank you very much for your attention. Hope not boring you all with these questions.Cheers