Actually Jimspring, I would say that there really doesn't have to be either faulty construction or installation to have the differences in condensation on exterior lites.
There are a number of minor things that could affect the formation of condensation that it can be very difficult to pinpoint a specific one way or the other.
I have seen the same question as yours reversed...in your case it was cooler outside and warmer inside. Well, what if it is cooler inside and warmer outside?
Can you still get condensation formation on the exterior of the windows? Yep.
Ultimately, the window, specifically the LowE coating, is designed to stop heat flow thru the glass. If the outside is cooler, as in your case, then the space between the lites can warm up to temperatures close to inside the house but the LowE will block that warmth from penetrating to the exterior of the lite, thus allowing the outer surface to be below the dew point, and condensation will result.
On the other hand, if it is cooler inside, then the cooler indoor air will penetrate into the spacing between the lites as well. But, in this case the warmer outside air is prevented from passing into the space because of the LowE coating...which is applied on the number 2 surface of the IGU (insulating glass unit - the term for dual or triple pane glass). The number 2 surface is the inner side of the outer lite.
Anyway, the LowE coating is metallic, so it can cool down based on the temperature inside the glass airspace and that would cause the exterior lite to cool to a point below the exterior dew point and again, condensation would result.
Really simple concept, but many variables involved! That some windows condensate and some don't, even if right next to one another, is not necessarily a flaw. It may be an environmental issue as simple as the shape of your indoor ceiling related to airflow against the insides of the unit.
Jackblack, you were referring to the LowE coating I believe. I hope this helps clarify it a bit for you as well.
And the way to check for a LowE coating is to hold a match up to the window when it is dark and watch for the flame reflection.
You will see three reflections in a LowE unit. The middle one is the LowE reflection and depending on whether it is closer to the outdoor side or indoor side (other reflection) will tell you which lite has the LowE coating.
Jackblack, good point about installation of the IGU and which lite the coating is on. The coating being on the #3 surface, versus the #2 surface, could have an effect on condensation and performance.
There is a difference on which surface you want the coating on depending on which coating you use (there are really three different species - and several sub-species), and your specific environmental location (heating, cooling, both). But, about 85% (or more) of all LowE coatings in North America are on the #2 surface. About the only exception is if you live in parts of Canada or extreme mountain or northern areas of the US.