http://www.netfunny.com/rhf/jokes/96/Jun/nosmoke.html

For monitoring PwrButton
$ evkey -d -t -1 /dev/input/event0
or there is a counter
$ cat /proc/interrupts
376: 8 twl4030 PwrButton
here says 8, but there was 4 pushed the pwrbutton

For "disable" it: in /etc/mce/mce.ini you can change PowerKeyLongDelay=1500 value to some big number.

I can tell you a story.
A story of my Jolla phone.
A true story.

My Jolla phone started randomly rebooting at some point. I only noticed it when I enabled a SIM card PIN: at least once, sometimes more times per day, when I pulled the phone out of the pocket, I found it waiting on the "enter SIM card PIN" screen. I could not think of anything that might have caused that other than an OS update I did just a few days before, so I naturally blamed that OS update.

I noticed that the random reboots were a bit less frequent when I carried the phone in the shirt pocket than when it was in the trousers pocket. This is when I started suspecting that maybe, just maybe, the battery may have something to do with it: the phone experiences more vibrations from walking when in the trousers pocket. On the other hand, I witnessed quite a few random reboots when there were seemingly no vibrations at all, like for example while typing a reply to an SMS.

So I went back to suspecting the software and, like you, I ignored the good advice to do something with the battery. I spent at least three months in this state, trying in vain to find the package responsible.

Eventually I gave up and added a folded piece of paper under the battery to push it more hardly against the contacts, as the people had been suggesting to me all this time. And guess what? Random reboots stopped immediately and completely.

End of story.