Do you experience problems during downloading?
Check your connection in Status and Interface settings window.
Use Test Server in Config > Servers.
We will probably ask you to do a test using only basic settings.
Do you experience problems during repair or unpacking?
Enable +Debug logging in the Status and Interface settings window and share the relevant parts of the log here using [ code ] sections.
Nope, this user is using the normal init.d script.
TS: see if there's anything useful in the program log files (under .sabnzbd/logs/ in the home dir of the configured user). Might also want to post your /etc/default/sabnzbdplus, and check (sudo netstat -lntep) there's nothing else on the port for sabnzbd (defaults to 8080).