Originally Posted by uknapster
thanks for you responce, but it is still the same, any other ideas bud
It appears you /etc/apt/sources.list is somehow in error or corrupt, or a sub list such as the Medibuntu one if you have installed that.
Open a terminal window and type
sudo apt-get update
and see what error it pops up, probably same as the error message you are getting now, but maybe a bit extra that will give a clue.
then select Setting -> Repositories
On the first tab select "Download from" and change it to some thing else. Use the main sever, or if it is the main server try a mirror.
On the second tab deselect all the third party software
On the third tab "Updates" deselect all the Ubuntu Updates
click on close and the program will prompt you to reload
click on the reload icon (top left)
If it reloads without error you can put back the third party and updates one at a time until you find the culprit.
You may also try sudo gedit /etc/apt/sources.list
and look for any obvious errors, like the d missing from deb at the beginning of a line.