Duplicate sources.list entries

[Georgi Kourtev]

Dear all,

From some time I have issue with duplicated entries in sources.list. When 
running aptitude update or apt-get update I got the below message after at 
least 2 to 3 minutes of reading the sources. I have tried some suggestions 
found over the internet but nothing helped. Any ideas?  Thanks.
gk

Reading package lists... Done
Updating debtags database...... Done
W: Duplicate sources.list entry http://archive.ubuntu.com karmic-
backports/main Packages 
(/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_karmic-
backports_main_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com karmic-
backports/restricted Packages 
(/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_karmic-
backports_restricted_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com karmic-
backports/universe Packages 
(/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_karmic-
backports_universe_binary-i386_Packages)
W: Duplicate sources.list entry http://archive.ubuntu.com karmic-
backports/multiverse Packages 
(/var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_karmic-
backports_multiverse_binary-i386_Packages)
W: You may want to run apt-get update to correct these problems