This happens if the recent event on the home page is the question being answered instead of being asked, i.e. it's listed as "answered X ago" instead of "asked X ago". The link changes as appropriate.
In any event, if you want to change that, remove the following line from qa-app-format.php:
$fields['url'].='#'.qa_html(urlencode($acpostid));
This will also affect other places where there are direct links to answers or comments on a question, rather than the top of the question page.