For the past couple of hours tivo keeps rebooting every 15 mins. did have a problem a couple of weeks but tivo corrected itself.
Now got a message saying "the dvr has detected a serious problem and is attemting to fix it. this will take about 3 hours. please do not unplug or restart dvr! if, after 3 hours, the dvr does not restart, please call customer support". looks like i will be calling them in morning then.