For anyone that's had an issue with getting XDebug to work with the Debian linux distribution, you might want to check out this helpful hint Carsten Lucke has posted about.

This week I started to setup a Debian-based (Etch) web-server with PHP 5.2 in a virtual-machine with VMWare. Part of this setup was getting XDebug2 integrated. It's really awesome and my students definitely need to learn about it. [...] Building went well as usual but when I tried to integrate the extension inside php.ini it was all weird.

His system kept throwing him an error when he tried to load the shared module using the zend_extension directive, hand things happened. Loading it normally worked (so he knew it wasn't the module) and he finally figured out the problem:

But I need to enable it as Zend extension. Whatever. I finally used the full path to xdebug.so to load it [...] that worked.