Vaadin 6 and Font Awesome compatiability issues

I was wondering if there are any known issues with using Vaadin along with Font Awesome for Vaadin 6.x?

It seems like cool technology but I’m a little leery of using a library that depends on very sophisticated CSS given that IE 9 doesn’t even handle drawing buttons with gradients and rounded corners properly even using their proprietary CSS.

I am aware of the Vaadin 7 only plugin which uses Font Awesome and it appears to have issues with light testing:

For example the demo link is very slow ( and with Firefox 22 is experiencing rendering issues as described here:

And this doesn’t look too good either

But other non-Vaadin sites have reported success using it.

My main question is there any danger of Vaadin and this library running into compatibility issues given it’s relative complexity?