[ubuntu-uk] Error during update - duplicate entries

[Dianne Reuby]

I'm getting this error on update:
W: Duplicate sources.list entry http://archive.canonical.com/ubuntu/
lucid/partner Packages
(/var/lib/apt/lists/archive.canonical.com_ubuntu_dists_lucid_partner_binary-i386_Packages)

I've looked at my sources.list file and can only see one entry for te
partner repo:

## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and
the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu lucid partner
# deb-src http://archive.canonical.com/ubuntu lucid partner

Should that be commented out? I haven't edited the file since doing a
clean install of 10.04

TIA
Dianne