aptitude unable to find dependencies, broken packages

Question

I installed an ubuntu on a virtual machine 6 months ago. I never needed a ssh connection until now. But when I try to install sshd, I get this error:

root@onur-vmdesktop:/home/onur# apt-get install openssh-server
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
  openssh-server: Depends: openssh-client (= 1:5.3p1-3ubuntu3) but 1:5.3p1-3ubuntu5 is to be installed
E: Broken packages

What can I do?

Answer 1

I would suggest

 aptitude update
 aptitude upgrade
 aptitude install openssh-server

and you can replace aptitude with apt-get systematically.

But I would believe that http://askubuntu.com/ is a better place to ask.