I have never heard of this issue before. I assume it's not a demo version.
Is the resolution of your display settings (graphics monitor) set excessively low, less than 1024 for instance.
If that's not the case, try reinstalling / update NR-2.0 to the latest build. (NR-2.0 h) http://www.sonycreativesoftware.com/download/updates/noisereduction
No, this is not Demo. Actually, in demo mode the tabs are there, but after registration, they disappear.
I have 2.0h and I have uninstall and reinstalled Noise reduction several times.
Display is set to 1920X1200
And I'm running Vista 32bit
If I choose (in Noise reduction window) Plug-in Chain and select whatever audio plug-in, the tabs will appear in NR, but the other plug-in will not be in chain, actually I cannot add any other plug-in in to chain.