Component Reference (SDK 3.0) page 39 says you can use this here, but the debugger says the function isn't found, so it doesn't work. What I wanted to do was use the ad banner to act as an option button. I have it download the graphic since it can't be local. When the user selects the ad, it does its thing and updates the screen - if usestablefocus could be "false", then on the next call to show() it would highlight the first item in the content or category filter again. What I ended up doing is when it's done with its task, I use SetAdSelectable(false) to force it to move the select box where I want it, and then SetAdSelectable(true) to allow it to be chosen again if needed.
In any case, if the UseStableFocus isn't going to work on the poster screen, can you remove it from that section of the poster screen documentation please?
I kind of thought it was a mistake because it refers to buttons, but the "ad banner" could act as a button, ...well, you get where I'm coming from.