Hey,
I managed to find a way to use a backup from A02 after upgrading to the A05 firmware and still have Windows Media Player 10 working.
The problem I found was that once you restore from an backup made on the A02 firmware, some of the registry keys for Windows Media Player 10 get lost. So I figured after freshly installing new firmware I could export the Windows Media Player 10 registry entries.
So then I restored from a backup made on the A02 firmware, then I imported the Windows Media player registry keys after restoring and then windows media player found the skins happily.
I have attached the registry entries you need.
You will need to install TascalRegEdit v0.83 on your pocket pc first. It's free so you don't have to worry about trial versions or anything like that.
http://www.freewareppc.com/utilities...lregedit.shtml