I can't stand using the escient on RTI stuff. My boss got one in to try in our demo set up and I just could not make it work satisfactorily using any of the interfaces. If it weren't so slow I would like the one they designed to fit on the RK3 screen, but they need to recode it so it doesn't refresh the entire page every time you do something. I would probably be happy using the full page RK4 interface if the buttons weren't so stinking little and if the UI were designed better for 640x480.
But yeah... to answer the actual original question, I don't think it has anything to do with your RK3. If I access the interface through any web browser I get basically the same results.
Unfortunately unless they make the fireball work a little better on stuff like RTI's products it's not going to stand a chance against something like the apple tv.
Now if they develop a way of making an apple tv work (by actually touching what I want) on a T4 then sign me up... that interface would look splendid in 640x480, even if they make it really inconvenient to use it in that resolution