Not technically a "problem" - the rules allow you to get the ticket issued anywhere you want, however, unless you are issuing the (ex-ICN) ticket in Canada you will pay the higher of the 2 fares (between the fare for ICN and the fare for where you issue the ticket - which will generally be the fare for where you issue the ticket).

So - if you're okay paying the higher fare, get it issued anywhere you want (the RTW desk should be able to do it and charge you the US rate etc.)... If you want the ICN fare you'll need to use the AA GSA in ICN or a travel agent based in ICN. The GSA requires you to be present in person to provide payment (even via Credit card) - there is a travel agent that has been used somewhat successfully - if you want I'll PM you their contact detail. I have not used them yet - so it's at your own risk.

Good luck.