[Config] Extremely slow

I have a XML-File with let's say 700 lines of data. When reading this configuration it takes a bunch of time till the operation is finished. However, I'm able to use a cache-mechanism: once in a while the XML-File will be written as a PHP-Array into another file, from which the configuration will then be read. Anyway, this is not quite the solution I'm looking for: Has annyone suggestions where I should look for a bottleneck in my system-configuration so reading the xml-file will get faster? Here's my code: $oConfig = new Config; $this->oConfigRoot = &$oConfig->parseConfig($sPathToSettingFile, 'XML'); $aOpenedFiles[$sMD5Hash] = &$this->oConfigRoot; // var_dump($this->oConfigRoot); Btw.: When un-commenting the "var_dump()" statement, I get a "Nesting level too deep"-Fatal-Error... Regards Thorsten