Not a bug - v9.1.8 allows you to interact with ForumsPro and this is done by first setting the Forum Type, then setting the Forum Module Name.
IF
$blog_conf['forum_type'] is empty (zero)
THEN (we are using CPG-BB)
Fix_Quotes(message_prepare($message, $html_on, $bbcode_on))
ELSE (we are using ForumsPro)
Fix_Quotes(forumspro_message_prepare($message, $html_on, $bbcode_on))
Function forumspro_message_prepare() exists in "includes/fpbbcode.php" and that file is loaded whenever $blog_conf['forum_type'] is set greater than zero i.e. ForumsPro. That function exists in ForumsPro 2.0.0.1.
So, what Forum Type do you have selected in Blogs admin? Sounds like you have CPG-BB selected?
I removed ForumsPro v2.0.3 from downloads when Rayvenhaus said he was reviving myndworx