It seems like a permissions error. Just a thought, but do you know if the udev rules file ("95-pentax.rules") has been installed in the /lib/udev/rules.d directory? This should happen automatically during the install process, but it looks like perhaps you are building the driver manually and running it in a debugger. If you haven't done a "sudo make install" for libpktriggercord (and I think maybe rebooted for good measure), it might not have been installed properly, and that might be the source of the problem.
If it's not that, have you tried pktriggercord on your system? Just curious if that works.
I'm losing track of what i need to be testing. What exactly did the new cable fix? The error you were getting over DC power on your cigarette lighter? That would be great, because I have no leads on that.
I tested the bias frame issue, and I don't get a crash, but I also don't get a picture. It says something about the exposure needing to be greater than 0. Ekos must be doing something different that the driver's not handling yet. I'm looking into that right now, as well as the shutter speed problems for exposures less than a second.