TiVo has been rolling out a firmware update that has given some DVR users a lot more than they were bargaining for. Officially, the refresh supplies Mini, Premiere and Roamio units with a very helpful page for default recording options as well as a host of bug fixes. However, that's when it's working -- quite a few subscribers have been dealing with glitches instead. Some Mini users have received an error that prevents installing the update without unplugging the set-top box for up to three days. Meanwhile, others have seen some of their gear roll back to older code, which can wipe out customizations and break multi-device setups. There are reports of spontaneous reboots and other hiccups, too.