Yes, each program has its own address look-up issues. No program is perfect, and each of us just wants a good balance between the features we need and the quality of the map data that comes with it.
I observed that most of the earlier-mentioned addresses that I was unable to find, I can actually find if, instead of entering Toronto, Ontario into DeLorme Street Atlas 2009, I enter what the program thinks the correct name for the city is. To find out what SA 2009 wants me to enter, I first zoom-in on the desired area on the map, and chances are that the town name will be there (at certain zoom level).
So for example, instead of entering the correct address:
500 Murray Ross Parkway, Toronto, Ontario, Canada
to look it up successfully, I would have to enter into SA 2009:
500 Murray Ross Parkway, Black Creek Village, Ontario, Canada
I can guarantee that if you go to the above area of Toronto, and ask anyone on the street what city they are in, they will all unanimously say Toronto, Ontario - no one will say they live in Black Creek Village, Ontario .