Only as an additional hint, maybe the issue was with the authorizations of the target script:
add > dont-require-permissions=yes > name=scriptnw owner=admin > policy=> ftp,reboot,read,write,> policy,> test,password,sniff,sensitive,romon:
The dont-require-permissions=yes is needed to run the script from Netwatch
The policy=policy is needed to have access to global variables.
See:
http://forum.mikrotik.com/t/global-variable-dissapears/127780/1
In an alternate universe those would be called with proper names 
, but we have to deal with what we have in this one 
…