require_once versus include_once

We have a problem in that require_once and include_once can include the same file. Now, if you have an application that dynamically includes some code - maybe it dynamically includes PEAR.php if it needs it - and it also always uses, say, the new Socket.php from Stig that uses PEAR.php - then you can get a collision. Maybe we can resolve this with a convention, like "always require_once base classes (DB.php, PEAR.php, etc), and use factory methods to dynamically include subclasses". Am I being clear? Does anyone else see the problem? -chuck -- Babies have self esteem. They are born loving their toes and finding them fascinating and delicious.