I got a piece of email today from Sascha Schumann about the issue of installing mod_perl and PHP together. In his own words: "The problem was caused by mixing object code with and without Large File Support (LFS) in one process. APXS provides a lot of unnecessary information. PHP applied a strict filter to get only useful things. That filter missed settings for LFS, so that PHP was always compiled without LFS." If you are having issues with this, you can check out the latest snapshot here, which is patched to solve this problem. The fix will also be a part of version 4.0.4 when it is released.