When switching themes in blocks, theme stays the same
Ended up using hefox's (from Drupal comments) fix

&lt;?php
function realname_user($op, &amp;$edit, &amp;$account, $category = NULL) {
    global $theme;
  if (!$theme) return; // prevent realname from overiding theme on block pages
?&gt;


I did add in my own code as a safeguard, in the if statement, the condition that we were on the blocks page.