Different tools have different methodologies for determining where an ad is served.
Misreported or misunderstood data
It's possible that the data you are relying on to determine where an ad was served was reported wrong by a third-party tool or the data being reported was misunderstood.
If you're using a third-party tool to determine where ads are being placed, carefully investigate how the tool determines location. It might determine location differently than iPromote. It also might do it poorly.
For example, the tool might report the server the ad was served from, not the actual location of the client where the ad was served to.
Geo data mismatch between tools
Sometimes two different analytics tools display location data in a way that makes them appear to be the same data, when in fact they are different.
For example, one tool might display a field that shows the source of an ad. This is not misleading; it's possibly quite useful. However, another tool might consume the source data and display it in an ad destination field, which is misleading. An ad source is not the same thing as its client destination.
Compare apples to apples. If data between tools does not correlate, you might need to use APIs or a spreadsheet to create the report you want.