How do I get transparency to work in Blackberry OS4.6

I want my application to home screen to look like the default home screen for the 8520. A background image, and a top translucent bar at the top, and translucent bitmapfields accoss the bottom.

I am using OS4.6

On my mainscreen

1. I have a horizontalfieldmanager (topManager) and a verticalfieldmanager(contentManager)
2. I have set the background image for the contentManager
3. I have added another VerticalFieldManager (buttonSet) which is a ListStyleButtonSet taken from the AdvancedUI examples and have set its background to setBackgroun开发者_JS百科d(BackgroundFactory.createSolidTransparentBackground(0x00000000, 150));
4. The buttonSet appears opaque, no transparency

What am I missing? Is this a problem with OS4.6 or are my fundamentals off? Can anybody point me to a working example?

Thanks in advance?

BackgroundFactory class is not supported in the 4.6 OS And everything else looks fine. The API ref for 4.5 OS " http://www.blackberry.com/developers/docs/4.5.0api/ "