I just installed SF (it is great, by the way) and found that I had to change the variable for the breadcrumbs "Home" link to get it to work properly. For most people the default setting probably works fine…I assume because for most sites the "WordPress address" and "Blog address" settings are the same. But for people like me who have WordPress installed in a subdirectory but the index.php file in the root, the link doesn't work. Rather than point to the siteurl it had to point to the homeurl. So, here is the simple code change I made to fix it:

 \simple-forum\sf-pagecomponents.php (line 111)

Default Setting:  $out.= '<div class="sfmessagestrip"><a href="'.get_settings('siteurl').'">Home</a>'."\n";

Changed to:  $out.= '<div class="sfmessagestrip"><a href="'.get_settings('homeurl').'">Home</a>'."\n";

 That seems to have solved the problem.

I noticed this too. Luckily I came here to find the answer and here it is! THanks