I am really confused at the moment! While using Platinum, Concrete Limiter only appears to have an effect on the 'gain' of a track and not the track 'volume'. Is this the intended behaviour? Please forgive me if I am ignorant of how it is designed to function.
 
If I drive a track volume above 0db, Concrete Limiter will not reduce the level. It will only do so when I overdrive the gain. Inserting a brickwall limiter into the track FX will not limit the overall volume either. Consequently, it would seem that there is effectively no way to limit the overall volume of an individual track. Am I missing something? Or is it because of the amount of Cabernet Sauvignon I had with my meal tonight?

Inserting a brickwall limiter into the track FX will not limit the overall volume either

 
Erm, yes it will, depending on what controls are exposed by the specific plugin.
 
Can't speak for the Concrete Limiter as I'm a) not at my DAW and b) don't use it very much.
 
BUT  - you shouldn't be driving your tracks that close to 0dB in any case.
If they're too loud, turn them down and everything else with it. (Grouping faders is a good idea)
 

Normally I would never ever drive my tracks that hard. However, this is an experiment brought on by some behaviour I encountered on a project that made me wonder what CL was doing. 
 
I totally agree with you - that a Limiter should work on the overall volume. I have a little video of what it is currently doing ...  http://youtu.be/xSY2jg1wtRQ
 

Off to bed now, I'll check back in the morning to see if anyone can add further explanation. 

One thing you need to be sure of is, is the PC post FX bin or not? If not it can't be in control of the volume.

Yes, I have it set to post FX bin - which is why I'm baffled.  

A number of limiters work with auto gain makeup. Meaning as you reduce the threshold, the actual volume will go up - with the peaks being increasingly reduced, the RMS volume can actually go up. Perhaps this is what's happening?

The reason the volume fader is peaking the output is because it is after the limiters in the signal flow. If you look at the signal flow chart for Sonar you will see that the volume fader is post effects and post PC. Even if you have PC set post effects it is still pre volume fader. The gain fader is actually pre everything.

I hear what you are saying teego, but then how can I ever limit the overall track volume? (Apart from manually keeping my eye on the meter for peaks. I would really like a limiter as the last item in the chain. 

I am not sure I understand what you are trying to do but if you want to reduce the volume with the limiter pull the output fader down on the limiter or just reduce the volume coming in with the gain fader.  I generally use a limiter to limit the peaks, if I want to lower the volume I just turn it down before it gets to the limiter at the gain fader or any effects output that may be ahead of the limiter.