Ok. I've catch up something that might help you.

This is not standard behaviour as far as I know and might be determined by webKit engine.
When I am trying to type some text in to the Input Field using HD keyboard, focusing the field works fine. But when you type in first letter this I/0 input triggering continuously the last letter. There is nothing to stop this. For me it looks like enter frame listener running on top of flash and triggering this data. I wonder if that behaviour is not related to only text field but some other flash functionality that might be a reason why some games are getting stuck. I can try to deal with many different situations and find some way around inside flash but obviously for content that was done is noting to do with this.

Another one thing, stage resize listener is not being triggered when you change portrait and landscape mode. So there is no way that flash can dynamically update all of the elements. Of course it's related to content that was designed for this purposes to be a liquid.

From what I see after some testing:
WebKit - the best performance but can cause the issue mentioned above.

WebKit(html loader) doesn't load some external components sometimes and I can't find a rules for that. If will, seems to be related to issue above as well, but this time you can't enter anything to any input field)

MicroB - just redirect you to the native browser, so standard behaviour.

KMPlayer - useless wen flash game required any external call, to xml database java script or another swf witch is very often practice in flash game development. Also waste of screen space.

Hope it helps.

(N900, leaked 1.2, no overclocked but system version is 2.6.28.10power27, flash player 9.0.260.0)