Thanks. Good catch. Will try to do this for the beta.
I aggree with you about font sizes in the themes. The recommended approach of jQuery UI team is to use
font-size: 62.5%;
This approach IMHO is not good and it works if you load the page, but if you try to add dynamically a UI Widget it does not work. Example. If you have tab and try to add dynamically (via url) a accordion whitin tab you will have a destroyed font size for the accordion. Try it.
This is the reason that I have set a fixed font size for all grids.
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