Some people have been having troubles with WordPress on PHP 5 under certain server configurations. We’ve done a lot of investigation into the issue and there is good news and bad news. The good news is there’s nothing wrong with WordPress. The bad news is there’s a bug in PHP 5.0.0 that causes Apache to segfault when you login to WP. However whatever the bug was in the initial PHP 5.0.0 release, it seems to be fixed in the PHP CVS. So if you’re already on the bleeding edge with PHP 5 you might want to push a little further to the latest nightly PHP build. We’re certain this will be addressed when the PHP folks release a bug fix for their first PHP 5 release.