Just out of curiousity why (and how) were you converting your mono track to stereo? You probably have it figured out now but it could be helpful to others... (and as I said I'm curious).
 
It took me a long time to figure out the relationship (and how to set up) my mono signals > the stereo busses. Still get a little confuzzled with the whole "stereo field/image" stuff but for more "advanced" reasons.
 
And just in case the reason WHY you wanted to convert to stereo is to get more depth/spread... for a mono signal like guitar the absolute BEST way is to really practice the track/performance so it's ultra tight, record it twice (into two separate tracks or into one then clone and choose two of the best takes that work well together) and pan them left/right to whatever degree sounds best (start at 100% and inch both sides closer to center to see if they sound better that way).
 
For a SINGLE guitar track that you cannot duplicate the performance of (like an improvised blues solo or something or maybe you don't have access tot he original artist to do a proper double) then you can clone the track and use the Haas effect... which is delaying the second signal by x amount of milliseconds (keep it under 30ms otherwise it turns into an "echo" effect). You can do that by manually nudging the clip of the second track down the timeline or using a delay effect (I like Channel Tools for that because it's pure delay and is easy to use). Then you pan those two tracks left/right. It will create depth. Be careful about the delay though and try different delay lengths. You may induce phasing problems and it will sound wierd so play with the delay time.
 
I use that on solos I don't/can't rerecord and it is very good at fattening things up. Never as good as a properly played double track though.
 
Cheers.
 
PS: Everything I am talking about are mono clips/tracks so a single wave (not a double wave). The busses take care of the stereo field stuff as long as you do not hit the Stereo Interleave button on them (which sums the output to mono). Read up on "Stereo Interleave" buttons and mixing in mono. Totally different subject (kind of) but hitting the interleave button on a buss (including the master) can reveal "frequency masking" problems which then tells you to maybe EQ things a little better to get certain sounds/instruments out of the way.
 
Of course I'm still a n00b mixer but if you start looking into these things now you'll thank me later... (and yes I know I'm being a pompous ass but I see you hitting some of the same walls I did... you better teach me some stuff when you get better at all this than I am).