From an important notice posted on the main PHP.net page - a bug has been found with PHP 5.2.7 and it has been "recalled":
Due to a security bug found in the PHP 5.2.7 release, it has been removed from distribution. The bug affects configurations where magic_quotes_gpc is enabled, because it remains off even when set to on. In the meantime, use PHP 5.2.6 until PHP 5.2.8 is later released.
The 5.2.7 downloads have been removed from the downloads page but you can now redownload the PHP 5.2.6 source and binaries if you need them.
You can also find out more about the issue in this post on Stefan Esser's blog