if you find play back on monitor has some problems such as freezing, video jump, try troubleshooting methods below.
1. check if playback on all channels faces the same issue.
2. check if placyback on all recording of this channel faces the same issue.
3. format hard disk drive to erase everything in hard disk drive. record and check play back again.
4. restore system to factory default.(it won't delete video in hard drive)
5. send email to us and ask new firmware to upgrade system.