Henrik, I’ve been doing some test and first I thought that the problem was one particular cam, but then I realized that the problem begins when I add more than 3 cams. Everything works fine with 3 cams, but when I add another one, the problem starts again.
I also realized that in the web client it works fine, but I don’t understand why not in the soft client.
Hm, … If you only can use 3 cams, well … This is a long shot, but strange things happens sometimes. NCS rely on system resources and if it is a problem with them things can go wrong in my experience from another case. From an earlier post I think you reside in a Spanish speaking country. Either in Europe or we might be neighbors since I am in Brasil for some more weeks ;). However, set the computer that you have installed NCS on to only work in English (US) format, location, date, etc. So the computer is completely in English. Do not use any special characters in names, password, … Reinstall, remove config files also, NCS and add cameras again.
-Henrik
Henrik, I’ll be doing that in the next few days. I’m from Argentina by the way. 
I hope this procedure works.
Alternstive if you port forward the 4-5 cams thst causes problems for you so I can add them to my system and see if I get the vame result.