I've installed Phalanger on a 64-bit Windows 2008 machine running IIS 7.5. I've successfully mapped the .php extension to execute php scripts, but it seems like some standard PHP functions are missing. Currently I get an error that "version_compare()" is an undefined function. Any idea what might be wrong?
I've not experienced the exact problem you report but had something similar.
Have you made sure that 32-bit applications are enabled for the App Pool that you're using? Right click on the App Pool and select Advanced Properties. This should give you the option to enable 32-bit applications.