I have the same problem as the guy in this post. Except I'm actually using WAMP not XAMPP. Unfortunately, he gave up, so no solution was found.
This all came up when installing the Zend Framework. I changed my include path to include the Zend libraries, but gave me an error saying my include path is ".; c:\php5\pear". Which is not true. "pear" does not reside anywhere in my php.ini file. I ran phpinfo() and I am editing the correct file. Infact, I have been able to change other things and it reflect in phpinfo(), but no matter what I change the include_path to, it NEVER changes in phpinfo(). It always says ".;C:\php5\pear"
Running XP, BTW.