Already synchorised but not identified on next login

The delicate situation is when the user is already a site member and yet he/she is also a facebook member.
Did a trial on that situation on mysite, here are the results :
- Site user login using joomla login .......
- After logging in, he/she synchronised site account with his/her Facebook ID using the blue f-connect button.
- Results : - no avatar imported - no info imported (user keeps his original site info intact).
- Logging out and logging in again, using facebook ID, user is identified as joomla user as well as a facebook user (no new user ID is created) and nicely directed to friend invite page.
- Logging out and logging in again, using joomla ID, this is where problem found. User is not identified as synchronised user as the fb syncronising button appears again.

Is this the normal case ?? Pls assist. Thanks.