Application Icon transparency issue (Windows Phone 7)

I'm writing a Windows Phone 7 app and have a icon (both tile icon and app icon). The icon has my开发者_C百科 little logo in the middle surrounded by a transparent background. But when I see the icons on the phone emulator the background is black. It stays black regardless of what theme is chosen (light or dark).

I would expect that the transparent background would've been filled in with the users chosen Accent Color like all the other icons on the phone (ie, settings etc) but this is not the case.

Do I have to do anything special to have a transparent background? Thanks!

My understanding is it was supposed to have been changed to work the way you expect, but for the moment it's only working for 1st party apps. My understanding is this is a bug. A timeframe hasn't been offered for resolution to my knowledge.