Recently as I was going through the site testing out the features from our last update, I noticed that there are still a lot of users that haven't updated their themes in over a year. During that time, the themes have improved quite a bit from a performance standpoint but not all of these updates were automatically applied. For instance, originally all the website headers were created in flash, but they took a long time to load and for other reasons, all the headers are now exported to html. This dramatically improves the how fast your site loads up and enables it to work on mobile browsers.

How do I know if my theme needs to be updated?
The easiest way to see if your theme needs to be updated is to visit your website and right-click anywhere on the header. If a flash menu pops up then you still have the old theme.

How do I update to the new versions?
If you simply go in to edit your theme and hit the "save" button, it will re-export it using the latest version and your theme will be updated. To be on the safe side, you can do a "save as" and export a new copy in case you want to keep your old theme. Then when the new copy is exported you will need to apply it to your site.