UPDATE:
I discovered the IP had changed from fixed to DHCP! That explains why I couldn't reach the unit - that part of the problem is solved.
However, I still don't see any cameras in Live View but, when I go to Configuration/Camera Settings/Display Settings - I do see the live camera video...
I'm sorry my first post is a plea for help!
I have a DS-7204HVI-S Series Net DVR with 3 analogue cameras attached.
I've been using Firefox to 'Live View' the 3 cameras but lately I've noticed the video has been stalling, missing 10 or more seconds and then streaming again. This is annoying but...