Here are some other suggestions to try if you're seeing "Facebook (0)" in contacts: menu: view after letting it sit for ten minutes.
1. Make sure Google calendar sync is checked and auto sync is enabled in the phone's accounts & sync menu.
2. To reset Facebook for HTC Sense and try again, remove your Facebook for HTC Sense account from the phone's accounts & sync menu, and then on the desktop Facebook.com site, go to Account, application settings, authorized, and click the "X" next to HTC Sense to remove it. Then try adding it again on the phone.
3. To COMPLETELY reset your contacts and try again, make sure your contacts are backed up to Google or on your SD card, and then go to settings: applications and find Contacts Storage. Clear its data. Then it will re-download all your contacts from Google and Facebook, which will take a while.