Debug Magento Autoload problems with backtrace

gistfile1.txt

Temporary edit the lib/Varien/Autoload.php

gistfile2.php

public function autoload($class)
    {
        if ($this->_collectClasses) {
            $this->_arrLoadedClasses[self::$_scope][] = $class;
        }
        if ($this->_isIncludePathDefined) {
            $classFile =  COMPILER_INCLUDE_PATH . DIRECTORY_SEPARATOR . $class;
        } else {
            $classFile = str_replace(' ', DIRECTORY_SEPARATOR, ucwords(str_replace('_', ' ', $class)));
        }
        $classFile.= '.php';
        if($classFile == "File.php")
        {
            Mage::log(Varien_Debug::backtrace(true,true),null,"bcktrace.log",true);
        }
        return include $classFile;
    }