When I look at your profile timeline, I see a brief excerpt with a "see more" (which is put there by Facebook, not WPBook).
When I look at the fan page, I see a brief excerpt (same as profile) with a "see more" but when I expand the "see more" I no longer can see the "more" link.
Not sure why, since I'm sending the same in either case - it must be that Facebook is treating what it received differently.
When you say "the excerpt I specify in my SEO settings" - are you using an SEO plugin?
When I refer to the Excerpt I'm talking about the box right under the main post editing window, above "Send Trackbacks." If you define an excerpt there WPBook will use it.