Using the Update Manager I get an error message 'Failed to download package files' 'check your internet connection' after it runs for about a minute with message 'applying changes'. I am using a Dell mini 10 netbook. The internet connection is by direct Erthernet cable to a router and there are no problems as my desktop computer is working fine.
Using Ubantu 12.04 LTS
Error message 'Details' :
Failed to fetch http://gb.archive.ubuntu.com/ubuntu/...tu6.1_i386.deb 404 Not Found [IP: 188.8.131.52 80]
Failed to fetch http://gb.archive.ubuntu.com/ubuntu/...0.6.3_i386.deb 404 Not Found [IP:184.108.40.206 80]