Remacc.Ammyy detected as a threat - can't exclude from scans

I am running NIS version 21.7.0.11 on Win7. 
I run a Ammyy Ammyy 3.5 so that I can remotely access various PC's.  I installed the program some time last year, but since June 2015, NIS flags Remacc.Ammyy as a threat saying:

"Remacc.Ammyy is a remote control surveillance tool that secretly monitors and controls computers."

Well yes that of course is correct, but this is exactly what is is meant to do as it's a remote desktop sharing program.
I understand that there are various hacked and cracked version of this software, but I bought several licences and my copy is legitimate.  
The most annoying part is that I don't seem to be able to exclude the program from any scans, despite adding the .exe file and the various folder paths to these sections:

Items to Exclude from Scans
Items to Exclude from Auto-Protect, Sonar and Download Intelligence Detection

So every morning I am greeted with a red  "Threats Detected" box and the only way I can go forward is to click "Exclude" under the Action heading.  But that only works until the next time the scan identifies the "threat".  Particularly annoying as I run NIS on both the host and remoye PC's.

So my questions are:

1.  Why is this flagged as a threat?
2.  How can I add this program to the exclude list so that I don't get bothered with false positives?

Thanks