Well, it looks like the DOMXML module in PHP 4.0.5 changed significantly, causing all kinds of problems in parsing the messages from OpenSRS.
I've gone through the code and made the changes required to "fix" the opensrs-php class. However, THIS MEANS THAT THE CVS CODE WILL ONLY WORK WITH PHP 4.0.5!
I will eventually try and build in a switch to determine which version of the domxml code is running, and parse appropriately. But if you are running PHP 4.0.4 or earlier, DON'T USE THE CVS CODE!