MSN contatcts are lost/disappeared

Hello there
For some unknown reason all my contacts in my contact lists in both my Windows Live Mail and my Windows MSN Live Messenger with the same account were deleted/disappeared...Never ever experienced this before...I've had this account for about 8 years...

I'm using version 2009 (Build 14.0.8089.726) at windows live messenger.

I've not upgraded or downgraded my Windows Live Messenger.
It didn't crash either...How can it come ?

Extremely strange.

Please how do i recover all my losts contacts in my contact lists ?

Any good clue ?

Greetings
Tom