Indeed. Nokia's ****ish behaviour regarding this is pissing me off. I'm tempted to upload a nokia-av.ko file that doesn't disable the button.

--

I've figured out what happens: When inserting a headset, /usr/lib/ohm/libohm_accessories.so will register it to the system as plain headphones. Plain headphones do not have a button, so why would pressing it do anything? When the policy changes to "phone", this file will re-register the headset as a - *gasp* - headset; this is why (if you monitor HAL) you "see" the headphones being "removed and reinserted".

Making a replacement /usr/lib/ohm/libohm_accessories.so that would register the headset in the first place as a headset wouldn't be hard work (riiiight...) thanks to IDA Pro and the examples of plugins found in the OHM package but there's no point when you can just modify nokia-av.ko to not disable the button, which is what I will be doing soon. **** you, Nokia, and your stupid decisions.