i have this proplem
tamer@tamer-desktop:~$ sudo apt-get update -f
Hit http://packages.medibuntu.org jaunty Release.gpg
Ign http://packages.medibuntu.org jaunty/free Translation-en_US
Hit http://archive.ubuntu.com jaunty Release.gpg
Ign http://archive.ubuntu.com jaunty/main Translation-en_US                    
Ign http://archive.ubuntu.com jaunty/restricted Translation-en_US              
Ign http://archive.ubuntu.com jaunty/multiverse Translation-en_US
Ign http://archive.ubuntu.com jaunty/universe Translation-en_US
Get:1 http://archive.ubuntu.com jaunty-updates Release.gpg [189B]
Ign http://archive.ubuntu.com jaunty-updates/main Translation-en_US            
Ign http://archive.ubuntu.com jaunty-updates/restricted Translation-en_US      
Ign http://archive.ubuntu.com jaunty-updates/multiverse Translation-en_US
Ign http://archive.ubuntu.com jaunty-updates/universe Translation-en_US
Get:2 http://archive.ubuntu.com jaunty-security Release.gpg [189B]             
Ign http://archive.ubuntu.com jaunty-security/main Translation-en_US           
Ign http://archive.ubuntu.com jaunty-security/restricted Translation-en_US     
Ign http://archive.ubuntu.com jaunty-security/multiverse Translation-en_US     
Ign http://archive.ubuntu.com jaunty-security/universe Translation-en_US
Hit http://archive.ubuntu.com jaunty Release              
Hit http://archive.ubuntu.com jaunty-updates Release                           
Hit http://archive.ubuntu.com jaunty-security Release                          
Err http://archive.ubuntu.com jaunty-updates Release                           
  
Err http://archive.ubuntu.com jaunty-security Release                          
  
Hit http://archive.ubuntu.com jaunty/main Packages                             
Hit http://archive.ubuntu.com jaunty/restricted Packages                       
Hit http://archive.ubuntu.com jaunty/multiverse Packages                       
Hit http://archive.ubuntu.com jaunty/universe Packages                         
Ign http://packages.medibuntu.org jaunty/non-free Translation-en_US            
Hit http://packages.medibuntu.org jaunty Release
Hit http://packages.medibuntu.org jaunty/free Packages
Hit http://packages.medibuntu.org jaunty/non-free Packages
Hit http://packages.medibuntu.org jaunty/free Sources     
Hit http://packages.medibuntu.org jaunty/non-free Sources 
Fetched 378B in 22s (17B/s)                               
Reading package lists... Done
W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used.GPG error: http://archive.ubuntu.com jaunty-updates Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>

W: A error occurred during the signature verification. The repository is not updated and the previous index files will be used.GPG error: http://archive.ubuntu.com jaunty-security Release: The following signatures were invalid: BADSIG 40976EAF437D05B5 Ubuntu Archive Automatic Signing Key <email address hidden>

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jaunty-updates/Release  

W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/jaunty-security/Release  

W: Some index files failed to download, they have been ignored, or old ones used instead.
W: You may want to run apt-get update to correct these problems