To use the 'max_execution_time' time thing I posted above, you need to edit a file and insert it. I was suggesting include/config.php since that's included in every script.
I looked at line 7132 and still can't see what would do it. You could try disabling all your plugins by editing the include/config.php file and inserting:
Code:
define('DISABLE_HOOKS', 1);
just under the <?php line at the top. But this disables all plugins, so if you can't replicate the error then you probably don't want all plugins disabled for a long time.