strange routing error? Autoload not being called on some 404's.

[eluser]danmontgomery[/eluser]
Neither of these are bugs...

The 404 page is thrown when the router class is loaded, on line 99 of CodeIgniter.php. get_instance() is defined when Base4.php or Base5.php are included (line 140 or 144 of CodeIgniter.php) and autoload is run when the Controller class is declared (line 148 of CodeIgniter.php).

As for the log with a seemingly non-functioning router, there is either a problem with your controller or routing that is causing the page not to be found.