Is your system on line? I know a silly question, but most of the program
installs on Ubie require you to have a on line connection.

Ya, I have a working internet connection. (BSNL).

can you please open up the terminal and type in

sudo apt-get update

Then please post the reply back after you type in that command.

I am getting this same issue with trying to update my system from 6.04 to
feisty over the net. It starts the downloads but fails on multiple ones.

Now my problem was solved . But still i can't download codec
for the file whose extension is rmv. For this extension it gives me same error
Couldn't download all repository indexes !