Comodo defense +

I have a question concerning which is better. I noticed when I looked at windows vista security center it said I had two malware protections turned on "comodo defense + and nod32"
Does running the two together cause any known conflicts? which one is better. It gives me a warning about running 2 at the same time in security center. I would like to know which one is preferred to run. Since defense + is part of the firewall I am posting this here rather than anti-virus section.

When I first installed comodo I noticed I had two firewalls going - windows vista fw and comodo, so I disabled windows fw.
When I installed nod32 I noticed I also had a conflict warning since windows defender and nod32 were running together, so I disabled defender.
Now I also see when I have defense + enabled it gives me a warning that I have two malwares running at the same time. nod32 and defense +

Which is better to use while avoiding software conflicts and unneccessary system resource usage?

Thanks

 

D+ and NOD32 are perfectly compatible UNLESS you are using Comodo AV aswell, then thers a prob, if not then security centre is being an idiot.