Hello my friends "CookieRevised" and "Felu"..
First of all thanks for replying so we can discuss this matter a little bit.. The solution above really came from the Technical Support of WLM -i have no reason to lie about it, i only mean well and want to help others since it demonstrably solved the problem- so i post the exact extract from their email:
"
Delete WLDLOG.dll and disable themes:
1. Click Start (Windows Logo Pearl Button). Type C:\ and press ENTER.
2. On the window that will open, open the Program files folder.
3. Open the folder Windows Live.
4. Open the folder Contacts.
5. Delete the wldlog.dll file.
6. Next right-click the wlcomm file, click Properties.
7. Click the Compatibility tab.
8. Under Display settings, put a checkmark for Disable visual themes.
If the above steps do not resolve your issue, we would request you to collect the following logs and email it to us back at the earliest.
We will be waiting for your response so we can give you further troubleshooting steps if necessary. We understand the importance of you getting in touch with your contacts, so should the need arise for you to use Windows Live Messenger to get in touch with them, you may do so temporarily by going to http://webim.sg.msn.com while we continue to troubleshoot your concern. Rest assured that we will be here to assist you.
Thank you again for contacting Windows Live Messenger Technical Support.
Have a nice day.
Regards,
Windows Live Messenger Technical Support"
As i wrote before they suggested several things that i should try. I tried the least invasive way to solve this.. Nothing went wrong ever since..
Maybe there's some kind of conflict because of the updates for WLM (version 14) and/or the updates for Vista. It's definitely weird though..