οποιος εχει προβλημα στο facebook chat
1. Logon to your main Windows Live account http://live.com
2. Under your name in top right corner click "Profile"
3. In left column where it says "Connected to" click Facebook, if not there click "Connect"
4. Edit Facebook permissions to allow Chat
5. Then back to WP7 go to Settings | Email+accounts ... touch & fold facebook then sync. You will see it sync both facebook & windows live. Then you're all good, chat will be enabled straight away.