This is because of the Motorola Blur on the phone. I have both the original droid and the X. You can correctly download the Facebook app from the market on both but then that is where motorola screwed up.
On the original droid the regular app prompts you to sync all, existing, or none. The X overrides this option and automatically displays the inbox, sync interval timing, entirely skipping the contact sync.
Syncing Facebook contacts on the X requires you to go into Motorola blur's "my accounts" and select only their Facebook app. There it only downloads all of your contacts you have no choice. Also bet a lot of people don't realize it also starts the Motoblur social network app which you CAN NOT adjust, meaning there are no settings.
Motorla truly screwed up this section "My Accounts" because it counter acts with the official apps you can download straight from the market.