Why is map loading so slow or blurred?

Problem: Maps somtimes load very slow. Other applications like Google Earth load the maps much faster.
Reason: TrailRunner loads maps from internet services that provide free maps. If the loading process is slow, the map service is slow and TrailRunner can't get anything faster. Another reason are "fair use" agreements for commercial web services. This means that as long as you get maps in a fair amount and frequency, the commercial service won't put you on a black-list. For that reason TrailRunner throttles the keyhole imagery service.
Solution: TrailRunner caches maps. If you have once loaded map fragments from a service, it's unlikely you will need to load the same fragments again. The longer you use TrailRunner, the faster it will become.
Tip: In case the map material on the web service was updated, as it is frequently the case with openstreetmap.org, you can use the File > Consolidate > Reload background maps command to reload what’s currently visible or you can remove the MapViewTiles folder in your Application Support/TrailRunner folder.