what type of montoring are you using? headphones? or studio monitors connected via a single sub woofer ...??? could be an analogue issues in your monitoring chain (headphone cable, sub woofer bleeding into other channel)...
 
export the file from Sonar and re-import it and check the waveform display to see if the second channel shows anything (if zoomed) or if it is truly flat - if it is indeed flat, your "problem" in not inside sonar

MetalTeK
... but I can hear residual noise in the right.

what you mean by that? do you hear traces of your recordings or just noise - that later could be induced by improper grounding (50Hz/60Hz hum depending where you are)

Sorry, by that I mean faint guitar.

I don't have monitors, just a 2.1 speaker system, but I also tried with head phones.
I imported a wav sample just to bypass my interface altogether, and still the same thing.
Whether it is in stereo or after I convert to mono....when I pan 100% there is still some sound in the other channel

Also, the meters dont show sound in the opposite channel but I can clearly hear it, as ever so subtle as it may be, it is annoying as ****!

This is only one problem I am dealing with If I ever get this cleared up I still have CPU spikes, popping and dropouts,  
and other goofy crap going on when I am only using like 10% of my CPU and about 25% of my memory.
However, another thing I notice is when I am listening to a song my memory just continues to exponentially climb until I have to restart Sonar.
Even when I stop the song, the memory keeps climbing once I have pushed play.

I am wondering if most of my problems are related to Focusrites USB ASIO driver.

this doesn't really sound like a sonar issue. like you i'd be suspicious about the interface. have you checked if there is a new ASIO driver for your interface?
 
could you potentially borrow a different interface from a friend / retailer to see if this really your focusrite causing it?

FreeFlyBertl
this doesn't really sound like a sonar issue. like you i'd be su****ious about the interface. have you checked if there is a new ASIO driver for your interface?
 
could you potentially borrow a different interface from a friend / retailer to see if this really your focusrite causing it?

Also, try plugging into a different USB port (Not all are created equal).

MetalTeK

I Record on a dry track, no bus with Pan set to 0.  
Output set to Master
Now when I set input to Focusrite "Stereo" the meters only show sound in the left channel, but I can hear residual noise in the right.
When I set input to Focusrite "Right" nothing shows in the meters.
And oddly enough when I Set input to Focusrite "Left", both channels show input.

You are getting a lot of help of the thread and this description of recording a mono guitar on the left channel reads correct except for the "residual noise in the right".
 
If this is not happening at the audio interface, it could also occur if the PC Console Emulation has "Tolerance" enabled. The "Tolerance" feature introduces some crosstalk between the channels.

is it present in a mixed down wav or just during project playback?

Dear Cakewalk,
 
Please remove "suspicious" from the language filters. 
 
Thanks 

If it's just during monitoring while recording it shouldn't be a big problem. If you get actual crosstalk recorded in the waves I'd trade that card in as quickly as possible, that's just useless.

Are your master faders locked together and at the same level?