Bought this for my HTC Desire, and although the plug is the correct type, the fitting was way too snug and refused to actually go in. I pressed as hard as I dare to try and get the plug to locate into the phone, but in the end I thought there was a significant risk of breaking the phone, so gave up.
I have a colleague with a Blackberry which has the same socket, and it fitted that OK (if a little tightly), so I just passed it on to him. So I reckon the plug is out of spec by 1/20mm or something - there was nothing visible to the naked eye. It may fit your phone, I may have just been unlucky.