I'm still coming up to speed with the idiosyncrasies of the box (which radio to use when) so I'm happy to blame the user...I'm not doing any one thing specifically (other than having the Pineapple in client mode and hitting the management interface from wlan1 and finding it unresponsive.) I'll try to narrow it down to a specific behavior, but a situation where it's just sitting, doing nothing particularly strenuous and it just doesn't respond.
I've got it on the opposite end of the house (SIGINT is much more interesting there), and I'll notice after a day or two, that I can't reach it. When I checked this morning, it just had a solid green light.