Some problems are more common than others.
You should check out the archive first, in case someone already answered someone else who had the same problem as you. The PHP developers probably don't know about it, and unless you report it, chances are it won't be fixed. I had problems with php-3.0.12 installation on RedHat. Browsing through mailing lists, I saw that many people had the same problem, but no real solution was published, except for Sascha Schumann's message which pushed me in the correct direction. I get the same 500 error under IIS 5.0 in Windows 2000 Advanced Server.