The PHPWomen have posted a quick note about some of the broken-ness that's happened in the latest release of PHP, version 5.2, and the go-pear.phar file in the Windows releases.
Greg Beaver fixed it immediately, but the fix was NOT incorporated into the 5.2 releases for windows - however the file for the source releases is correct. If you are getting errors that look like this
If you're getting an error like they mention ("cannot use scalar value"), you'll need to go over and grab the latest Go-pear from the CVS repository and install it instead.