Stereo?

[dishe]

There is a KNOWN INCOMPATIBILITY with many 2.5 -> 3.5 adapters- I find it funny that it didn't even occur to you to consider THAT part of your connection!
This was the same way on the HTC Wizard and Tornado, and afaik all HTC phones that had a 2.5mm plug. It only worked with "True" 2.5mm stereo adaptors, and not 2.5mm adaptors made for phones, since phones usually made the first pin channel the mic instead (real stereo uses the first 2 channels for L+R, phones use Mic+Right, and stereo phones use Mic+Right+Left).

What you can do is pull the adaptor out just slightly, essentially skipping the first contact inside, and you'll hear full stereo sound! Problem is that this is a flimsy connection and will probably not stay connected.

Pick up a regular stereo (non-phone type) 2.5 -> 3.5 adapter from Radio Shack for $5, or get a Sony BT2500 a2dp stereo head unit like I did for truly wireless music... Bluetooth stereo is a lot cheaper than it used to be, and I can keep my phone in my pocket while the music comes out of the car speakers!