Apache2, PHP 5.2.8 Working - CRM Install Wizard Doesn't See the PHP Version

The Apache2 server and PHP version seem to be in order, but when I launch the CRM installer at

http://localhost/<CRM dir>/install.php

The wizard says I need a minimum of PHP 5.1 and preferably PHP 5.2.x. The thing is, I am running PHP 5.2.8, and I know this from running

php --version

Plus, I spent a bunch of time learning how and (I thought, successfully) compiling PHP 5.2.8. It is quite likely I screwed up and don't have some libraries I need, but I'm not sure where to look first.

Thanks in advance.

PS - I know some of you will suggest going to the CRM's forums... I tried this; these are not good. I much prefer the expertise I get here on the Stack Exchange sites.

The command line may run 5.2.8, but may have nothing to do with the cgi or module that apache runs. What does a webrequest with <?php echo phpversion();?> tell you about the version? Possibly use a full phpinfo() to check what's provided & where. Especially if you compiled a version of php by hand changes are high you did it only for the CLI package.