Old thread, but I am having the same issue. 2 recordings this past weekend said they recorded the whole program, but one (3 hour recording) stops about 8 minutes in, the other (1 hour recording) stops about 35 minutes in. Fully rebooted the box a couple times. No better. I guess I'll have to call Verizon and sit on hold for 1/2 hour.
Oh, and this is on a Cisco Cisco CHS 435 HD DVR