update manager will not work due to apt-get.
 

update manager will not work due to apt-get seems to be running in background.how to i set update manager to work properly?

Welcome to LQ

There is another instance of apt-get running, probably auto update.
Wait until apt-get has finished.

Kind regards

apt
 

Why is it running in the background? On a reboot perhaps run apt-get autoclean ?

Fred.

There are many reasons, auto-update is running, you are running apt from a terminal...
autoclean removes all stored archives in your cache for packages that can not be downloaded anymore.
It will not kill the running apt.

Kind regards

I'm not sure if you're experiencing the same problem I was, but maybe.
I had updates available I click on Update manager, it opened but never initialized, but said 68 updates.

My problem was that I wrote backports entry wrong.
Backports for lenny and squeeze are listed different, so , if you just edited your sources.list changing lenny to squeeze it's not right.
deb http://backports.debian.org/debian-backports squeeze-backports main
deb http://www.backports.org/debian lenny-backports main contrib non-free
Hopefully this helps.