I've found similar threads involving kernel panics, but that is not happening for me. What I *do* see is shutting down the zaptel service (either explicitly with 'service zaptel stop' or implicitly with 'shutdown -r now'), it complains that it is unable to unload zaptel and the rhino driver because they are in use. Stopping asterisk first avoids this. Threads I saw referred to renaming rc0.d/K92zaptel to rc0.d/K92zaptel so it will run after rc0.d/K94asterisk (this is from trixbox, btw.) Unfortunately, PIAF does not have a K94asterisk, so nothing (apparently) shuts down asterisk before the shutdown attempt on zaptel. I guess I can create a script K01asterisk and put a link to it in rc0.d and have it do 'amportal kill' or whatever - just wondering why that isn't already there?