Okay I found something in "adduser.inc.php"
00124: // Get rid of any unverified email accounts that are over 24 hours old
00125: $deldate = $html -> get_date();
00126: $deldate = $deldate - 86400;
00127:
00128: $query = "
00129: SELECT USER_ID
00130: FROM {$config['TABLE_PREFIX']}USERS
00131: WHERE USER_IS_APPROVED <> 'no'
Would this not delete users from the que after 24 hours!
Of course I did not copy the whole section but you will see that it purges the registration Que after 24 hours. At least it seems so.
My opinion is the Que should stay there until the Admin deletes it
