WLM 2011 Selecting Contacts to send messages

I have recently upgraded from Windows Vista to Windows 7 and my Windows Live Mail 2011 software was moved into the new Operating System. It is working perfectly except for a few minor problems like the following one.

When opening the screen for a NEW MESSAGE, and then clicking on TO
in order to select a contact from my List of Contacts, the following message will appear.

WLM can not open this contact. I try again twice or more times, and my list of contacts will then open allowing me to select the contact or contacts I want.

As this behaviour is not normal, I will appreciate advice on how to correct this
minor error.

Roderunner said:

...I suggest getting a hotmail.com account, store all your contacts in it, then use it to sign-in to WLM. Once done, if you don't need or use the hotmail account, it can be safely deleted. Now you will never lose your contacts.

It's a good idea to use hotmail contacts (contacts.live.com) to save contacts. You do need a LiveID to "sign in" with WLM, but you don't need to use the email address of the LiveID as an account in WLM at all. After signing in it should be possible to set up your contacts in WLM, and by doing so (while signed in) they will automatically be maintained at the website and available on any PC using WLM signed in to the same LiveID. If any part of WLM is not working properly, it may be worthwhile to do a repair of Windows live Essentials via Programs and Features.

Many thanks to both - roncerr and Roderunner - for tryng to help me.
However I am sorry to say I was misunderstood. The title of my thread shows that the problem is with Windows Live Mail 2011, it has nothing to do with my
server and the accounts I might have with my server. Incidentally my primary
account is oltiojose.espinoza@superonline.com . I have never lose MY CONTACTS, they are not available to me JUST FOR SECONDS, and this is
the minor problem I wanted to solve. I do have a hotmail account with a different
list of contacts. For each email account I have, my list of contacts are differents
and I have not lost any of them. And it is only with WLM 2011 that this minor incident is occurring.

Have already tried to repair WLM 2011 through Windows Live Essentials in Programs and Features of my Control Panel. It did not solve this little problem
which is proving to be stubburn and not easy to solve. Thank you to both
for your good intentions to help me.

As a test to try something different:
You said you have a hotmail account with a different list of contacts. You can make that list replace the one you have in WLM temporarily merely by "signing in" to WLM using the LiveID associated with your hotmail account. See if that list works correctly.

WLM 2011 is my default email browser, I do not need to sign in to enter into that account with my Server.
I click on the WLM2011 icon on my task bar and the mail is opened up, together with its list of contacts.
I do not understand how to implement your suggestion as I do not need to sing in to enter into WLM2011.
and I do not know if by importing the list of contacts I have on my Hotmail account, and replace the existing one I will lose the one I have, which I do not want at all. I do not want to apply a medicine that will be worse than
the disease. My problem is so minor, that I can live with it, but I thought there were easy solutions to apply.
If there are not then I will continue living with my problem.