encyclo - 1:13 am on Oct 10, 2010 (gmt 0)
You should also know this is a Joomla website and all Joomla websites have a <base> tag that is dynamically created for each page and every page. The path and file name in the <base> tag is equal to the current page, which is the proper coding according to W3C.
I don't use Joomla, but if the above is true then there is no reason for having a base element on the page at all. As lammert mentioned above, the base element is a mechanism for overriding the base href for relative links when it differs from the current page URI.
In general, the base element is more trouble than it's worth, even with "correct" usage it is bad practice. Of course, CMS developers don't always produce the best HTML markup, often the nature of a CMS leads to bloated markup.
See if you can simple comment out the base element from the head section, your site should work perfectly well without it and it is one less element to confuse Googlebot.