Actually, after a bit more searching, I found a response that might explain it.
I didn't know how to cite the post, si I've just pasted it in here:
"I had a hunch I knew what this is and a possible workaround.
If it was the headphone jack and ppl reporting all sorts of varying quality standard phones and jacks failing, it has to be the HTC control system, the physical switches which are the big difference.
The HTC headset 3.5mm jack has four connections (separated by the black bands) from the tip to the hilt. Standard jacks of course only need three. left, right and common. HTC's extra connection is the one right up by the hilt.
I selotaped to insulate this connector to try to eliminate it. So far 100% success. I've tried it on a few connectors now. Selotape is likely to wear over time so it could fail due to frequent use.
Technique:
You only want a layer two of tape. Wrap the whole plug in a layer or two , then using scissors, score a cut about 2-3mm from the hilt and scrape away the tape, leaving the 2-3mm on the plug.
i judged the 2-3mm by eye, looking at the plug that came on the HTC headset.
So it could be I'm right, or the tape is just seating the plug better. Either way it works for me.
G'luck.
exH"
