Recently I had some issues with my Facebook application not syncing properly. It pulled down most (but not all) of my contacts, and only showed the pictures for maybe 1/3rd of them all. I also did not see their status updates in my contact list.
After searching the internet for several hours, I came across a suggestion to remove the account, reboot, and then set it up again.
1) Open the Facebook app
2) Open Settings
3) Click 'Sync Contacts'
4) Change to 'Remove Facebook Data'
5) Click 'Ok'
6) From the Home screen, go into the Phone settings
7) Click 'Accounts & Sync'
8) Click on the Facebook account
9) Click 'Remove account'
10) Reboot phone
11) Open the Facebook app and set it up again
12) Set up the Sync as before
I don't believe Airplane mode is necessary, but that is exactly how I did it, and it worked for me.
This will completely clear your Facebook contacts from your phone, so after following the steps, you will need to go through your contacts and make sure you separate/merge your contacts as necessary. You may also need to scroll through your contact list for the Facebook pictures to start syncing as well.
You will also want to check and make sure your contact list is fine, I found out several days after doing this that it wasn't just my Facebook sync, but several of my contacts were corrupted as well.