Just updated to Wordpress 2.6 and Wordbook still works, but if I insert an image with the new caption feature, it seems to get confused and post some of the Wordpress code into Facebook, eg:
Last part of Dr Horrible online tomorrow. [caption id="" align="aligncenter" width="475" caption="Dr Horrible's Sing-Along Blog"][/...
Presumably this is down to Wordpress not actually converting the caption into HTML which Wordbook filters out?