How do I upgrade pear from 1.4.9 to the latest version?

Question

first off...

what is the latest version of PEAR?

It looks like it might be 1.7.2, but I didn't find any definitive, "THIS IS THE CURRENT VERSION OF PEAR" on the pear website.

I'm trying to upgrade PEAR on a system that I'm not all that familiar with.

pear version yields...

PEAR Version: 1.4.9
PHP Version: 5.1.6
Zend Engine Version: 2.1.0
Running on: Linux...

I ran pear upgrade pear and this message was included.

pear/PEAR dependency package "pear/Archive_Tar" installed version 1.3.5 is not the recommended version 1.3.3, but may be compatible, use --force to install
pear/Archive_Tar requires PEAR Installer (version >= 1.5.4), installed version is 1.4.9

Answer 1

The current stable version appears to be 1.9.0.

Answer 2

pear upgrade --force http://pear.php.net/get/PEAR-1.9.0