I will give you this Brian. You did a very nice job of explaining your concerns and what appears to be the consensus on the term true mono. I will let this thread fill out a bit more before I make another comment. I will say this though. I am a former Cubase and Logic user and never had a problem transitioning between them and Sonar. 
 
   

if cakewalk could shed some light on the internal routing of mono we could put this to bed, or at least finish speculating... a quick wiki gives plenty of info on "monaural" audio http://en.wikipedia.org/wiki/Monaural if you want to ponder the different "types" of mono... the recently posted signal flow diagram does not show this
 

John
... Please define "true mono". 

Using the Duality Principle, the dual of true mono is true stereo.
 
Walt

The OP's original reference may go back to an old problem with routing signals to mono outboard hardware, given that all of SONAR's outputs were stereo up until SONAR 8, which introduced mono hardware outputs for this purpose.
 
 
One of the things that complicate the discussion is that individual tracks have the ability to switch from mono to stereo and back internally, as needed. So if you insert a plugin that has stereo output, the track interleave will automatically change to stereo internally. But, as John T noted above, if the source is mono and the interleave is mono and you use mono effects, you do indeed have "true" mono - right up until the end of the chain, when that mono signal is ultimately sent to a stereo bus.
 

lawp
if cakewalk could shed some light on the internal routing of mono we could put this to bed, or at least finish speculating... a quick wiki gives plenty of info on "monaural" audio http://en.wikipedia.org/wiki/Monaural if you want to ponder the different "types" of mono... the recently posted signal flow diagram does not show this
 

Indeed somebody in Cake please blog this when they get a chance, polite request :)

Okay... I'm glad I'm not the only one completely confused about this mono stuff within Sonar. I never had to think about it before Sonar but there have been MANY instances where something I thought was mono or wanted to behave as mono was actually stereo. I just get worried about summing issues and really the whole thing confuses the heck out of me.
 
Like if I could just click Insert > Mono Track and plug my guitar in it would make me feel a whole lot less stupid. This also became a major issue when I started taking a good hard look at how Sonar was handling my drum sampler inputs (Insert Softsynth doesn't let you choose what tracks get what). I've managed to get my head wrapped around how to force the program to deal with these types of things but man... it was a real brain twister.
 
Not complaining... just saying it's confusing. Perhaps it doesn't even matter but I try to stick to certain principles and mono is kind of how I'm used to recording stuff. When everything is in stereo by default... I... well I'm just not sure what to do.