I have the HTC mini USB adapter (to 2 x USB + 3.5mm audio jack) and find then I get interference when it is simultaneously charging while playing music (or even when no music, but why would you want to listen then

. I thought it was some other device causing it, but it really does seem to be the charging of the Orbit II itself. It does disappear briefly sometimes, but then returns, just as I would expect if it was caused by the charging.
Can anyone else confrim this and/or suggest if it can be eliminated?