Ive tried the above hack - audio out works on the imagio yet i dont believe the functionality has been enabled. Explanation in this thread
http://forum.xda-developers.com/showthread.php?t=507995
quote - which I believe were taken from a HTC Support rep "While its essentially the same hardware in the Diamond2 and Pro2, and TV out is a function of the Qualcomm chipset, not all of the pins connecting to the chipset may be connected through to the extUSB port in the same way. " Imagio (whit100) has the same chip as the Diamond 2 and the Pro 2.