Peter,
I understand what you mean now - a portable USB device. I don't have that phone but I do have a Samsung U5 MP3 player that exhibits the same behaviour in Win 7 (no longer have XP).
I found some interesting references to Windows media player 11
that may be part of the problem, and to the drivers associated with the device. For example:
Windows XP: windows XP portable device, MP3 player, USB device
Perhaps there's something there that may point towards a resolution.
SD