Google Analytics now uses a new "asynchronous tracking" api rather than the old urchin analytics api that most of our older sites use. The main benefits of async tracking are possibly better performance, and mainly the ability to create goals etc. using the new api rather than the old one (you might for instance have an SEO consultant that needs to do this).
All our new sites use asynch tracking by default, but we can't just port the older ones over because of the chance that you've setup custom goals etc. using the older api - these won't work with the newer one unless you change them. If they were done by us as a customisation this would mean you would have to pay us to upgrade them, and for most clients, the benefit of the async api doesn't outweigh that cost. However, if you're confident you don't use such customisations, or that they don't matter too much to you, then you're welcome to switch to the async code.
If you would like to switch to the new Asynchronous Tracking, contact our Support team
and they can change the settings for your website.