I just wanted to install a disk manager with the help of ubuntu software center. To install this disk manager ubuntu asks me to insert the ubuntu CD/DVD. I inserted the CD and clicked on "Continue" (I translate from another language. Maybe it is another word, but I don't think so).
After I clicked on Continue ubuntu software center aks me to insert the CD/DVD again...but I put it already in the CD/DVD.
I also insert the same DVD with wich I installed ubuntu. Maye some necessary further info: Ubuntu Center asks me to insert: Ubuntu 12.04.1 LTS_Precise Pangolin_Release amd 64 (20120823.1)
The DVD's name is: Ubuntu 12.04.1 LTS amd64