I wouldn't recommend Defense+ and ThreatFire as, according to
this topic, problem will occur. Also, I'm sure there's other 'invisible' issues that haven't been discovered yet.
And if you use Avira Premium, you could disable Spyware Doctor, as Premium Edition of Avira includes spyware detection too. Of course, you could still use Spyware Doctor as an on-demand scanner.
Cheers,
Ragwing
And I wouldn't disable it

. I wouldn't rely on the antispyware part of antivir. Spyware doctor is the master chief in that sector for now. Why disabling it? Because it uses more recourses? perhaps, but you will have a 95% detection rate against a 80 (perhaps) % of antivir. So I would sujest keeping that enabled.
Xan