There are a significant number of results with people asking the same question if you search on the error number. A lot advise uninstalling and reinstalling, but this page on Yahoo! Answers of all places suggests clearing the cache and checking your firewall settings first.
The instructions for Vista are:
• Click Start and then click Explore to open Windows Explorer. On the Organize menu, click Folder and Search Options. Click the View tab. In the Advanced settings list, select Show hidden files and folders under Hidden Files and Folders. Clear the Hide extensions for known file types check box. Click OK to close the Folder Options window.
• Delete the Contacts Cache folder. To do so, right-click Start, and then click Explore to open the Windows Explorer window. In the Windows Explorer window, locate the folders below and delete all the files and folders inside them.
C:\Users\ Your Windows logon name \Contacts[Your Messenger e-mail address]
C:\Users\ Your Windows logon name \AppData\Local\Microsoft\Windows Live Contacts[Your Messenger e-mail address]
I haven't tried these to see if they work, so double check what you are doing at each stage.