If you've had issues with an "unsupported protocol" message when working with the PEAR installation on your PHP instance, you should check out this quick post from the PEAR blog with a tip on how to fix it.

When trying to install something, you will get the error: pear.php.net is using a unsupported protocal – This should never happen. install failed. This problem comes from corrupted channel files. Go into your PEAR php directory and backup .channels directory.

If you go into your PEAR installation and move the .channels directory out of the way then run an "update-channels" the issue should be corrected. Unfortunately, this also means you loose all channels you'd subscribed to, but does save you from having to reinstall PEAR completely.