simplexml and dom

Hi, I've been experimenting with using both simplexml and dom on the same document at the same time, and have run into a number of unexplainable PHP crashes unless I clone the domdocument object before using simplexml_import_dom() Is it a design goal of simplexml to be able to use it simultaneously with dom, or is it important to use either a simplexmlelement or a domdocument for the same structure but not both? If so, I will add a note to the manual, but I wanted to check with the creators first. A simplified version of the code I use is something like: <?php $blah = 'xml stuff'; // this is actually the contents of a package.xml extracted from disk $d = new DOMDocument; $d->loadXml($blah); // I do error checking here $sx = simplexml_import_dom($d); // manipulate document structure using dom // retrieve values using simplexml for simple tags ?> Thanks, Greg