Your current version in the page source code. I would advise that you open rapidweaver, hold command/option/7 keys. Go to the themes folder and remove the foundation theme. Then drag in the new one you downloaded. Restart RW.
The version of the theme is different than the version of the stacks. The theme is 1.7.2 and the stacks are 1.7.7 actually right now. You can get the theme here: http://foundation.joeworkman.net/theme
and check for updates in the Stacks plugin to get the 1.7.7 stacks.
Even though I downloaded and installed the foundation theme (from: Foundation 6 Stacks for RapidWeaver ) like 5 times. The older version refused to surrender its position.
After using your ‘command/option/7’ key command trick I was able to remove the stubborn ‘Foundation’ theme (control click).
By the way… Also noticed that most of the version numbers are visible below the tile of each stack and theme in the Manage Addons window. Very cool.
In my case, the outdated Foundation theme v 1.7.0 was displayed and it was easily deleted and replaced with the current version.