Found this on the HTC Forum Maybe this is the reason some work and some don't...My " guess" is the Thunderbolt jack configuration is Left ,Right, Mic, Ground.
Posted by jongalt26 on13 Apr 2011 9:00 AM on the HTC Thunderbolt forum
Im wondering if anyone knows what the pin assignments are for the audio jack. Im ordering a headset cable w/ mic and adapters and knowing this will save me $ on trial and error.
TRRS Connector pin order listed below = tip, ring, ring, sleeve
Typical iphone: Left, Right, Ground, Mic
Some Android Phones: Left, right, mic, ground
The HTC Hero, Desire & incredible followed the typical iphone assignments, can anyone confirm if they are the same for the thunderbolt?