There seem to be a couple of bugs in include/WlistBlock.class.php
In lines 159 and 163 the sprintf statement just substitutes the translation for date and time. These need to be edited to something like:
sprintf('%s', get_the_time())
Use something more ornate that %s if desired. To change the date format edit the parameters in the getthetime() function.
Also, in line 144 the conditional looks incorrectly for a 'showauthorname' value. Change to:
$request['showauthor'] == 'true'
This is a really excellent plugin!