G4-RTAHD cycling motion detection

[farmcam 0]

I have a G4-RTAHD 8 channel with 7 Intellicam dome cameras, 6 outdoor and 1 indoor. DVR output is HDMI to 32" HD TV. All cams set on MD. Here is the problem: if the DVR hangs and has to be rebooted or is powered down then after boot 4 (1 indoor and 3 out) of the seven cams will false trigger together exactly every 60 seconds 24/7 for 4 or 5 days then the cycling process will stop and everything will work perfectly. During the cycling, rebooting or a complete power off does not help and the system sometimes reboots itself. I haven't tried one reboot after another to see if it helps. Unplugging one cam at a time and then reconnect does not stop it, nor does pulling the HDMI cable. HDD status report is "normal" (1TB), but the HDD light on the front panel is on and the OM says it's suppose to be off. Dealer say voltage to unit not constant, but is supplied by UPS. So, I connect the DVR directly into wall outlet and bypass the UPS (but cams still on UPS), didn't stop it. Now before I go to the trouble of sending this unit in for some sort of repair does anyone have another suggestion that I might try? Thanks.