Hi Stefan, thank you fro your post, we are happy that you worked it out. One clarification:
PhpED is indeed PHP 5.2 compatible, even though PhpED installer doesn't instal PHP 5.2 - 5.2 is too new to be included in the distribution, peple would be screaming if we put such version in the installer. PHP that comes with PhpED is for local debugging anyway, 5.2 compatibility is in the fact that PhpED debugger (dbg) is indeed 5.2 compatible and can be installed on the systems running PHP 5.2 for the remote debugging. You didn't need to copy PHP 5.2 under PhpED - you could have installed dbg module compatible with 5.2 to your IIS and debuged right there, in the native environment - this is one of the strength of PhpED.
Our FAQ post on remote debugging is here:
howto-set-project-mapping-t2135.html
Remote doesn't mean that it is on a different machnie, it just means using the system outside of PhpED
Hope it helps.