That is a kind of WLM fact since 2009. 

I've created 2 differente accounts, with my domain.com and another with hotmail.com. 

The only difference between, its hotmail dont have problems with the site (people.live.com), your contacts database. The other domain received always a error "outlook connected" when I dont use outlook and either, in private browsing mode.

The contacts problem: I add 15 contacts or 20, and it only remains 5 on the WLM but online, it means, in the site people.live.com I've it all. I dont understand also why. I've clean the contacts cache on my desktop, install unistall and reinstall WLM 2009, 2010, 2011 and 2012 and it continues with the same issue.

Microsoft, please report this problem and fix it please.