You are correct RR and I should have guessed what your answer would be . In the case I am thinking of there would only be two images of different resolutions.

I recall a challenge we did some time ago of various locations from our CWBP and at the end you used your application to overlay our regional/area maps on the world map which was very cool. It also happens to have shown the very issue I am talking about because some of the entries did not line up as well with the original world map.

I guess in the end if the resolutions between the two are large enough it doesn't make any difference but if the world map shows any sort of features then to my mind they need to match.