[Sparkz]

PHP Code:

if ($bbcode == strtoupper($bbcode)) {
    $bbarr = explode ('.', $bbcode);
    $bbcode = "";
    foreach ($bbarr as $bbsentence) {
      if (trim($bbsentence) != "") {
        $bbcode .= ucfirst(strtolower(ltrim($bbsentence))) . ".";
      }
    }
} 


It only happened if the last letter of the text was a period.
I guess that's what you get for not testing your code properly
That should do it.