3rd party earbuds/phones not working with new Nano

Question

So, I've got a new Nano ( a couple months old at this point ), and the earbuds that came with it got accidently trashed.
No worries, because I've got several other sets of earbuds / headphones kicking around.
The problem is that with all of them, the sound keeps cutting out / playback stops.  I'm fairly certain that this is the iPod detecting "no headphones" and stopping playback.
It happens whenever the plug flexes; it's as if the jack briefly loses contact with the internal connectors.
Since I usually keep my iPod in my pocket, this happens quite often.
I don't know whether the new Apple earbuds (with volume control/mic) would react the same way; I won't buy them, because I can't have them at work (anything with a microphone is banned).
Anyone have thoughts / help?
Thanks!

Answer 1

Ok, more follow-up.
Roommate had a pair of iPod buds that he'd never used, and let me have them.
There are marked differences between the iPod 3.5 mm jack and a "standard" 3.5 mm jack.
The standard 3.5 mm jack has three sections, tip, middle, and call it 'core'.
The iPod jack has 4 sections, tip, middle, core 1 and core 2.
The seperator for each of the common sections (tip to middle/middle to core(core1)) are at the same place.
I suspect that the "core 2" is how the the iPod/iPad/iPhone uses the microphone.
No big deal, except I can't have a microphone, at all, period, at work.  Absolutely forbidden (if I want to keep my job).
Breaking out the micrometer (yes, I own a micrometer), it looks as though the iPod jack is a lot closer to the 3.5mm tolerance, than the standard one, which may be the issue.  That is, the core1/core2 sections are 3.5mm exactly, whereas the 3rd party jack is 3.46mm.  I wouldn't think that would make enough of a difference, but apparently it does.
So, I'm back to my starting point:
Is there an "approved for iPod" set of headphones that doesn't have a microphone built in?