There are multiple caching levels to be mindful of with a typical ArcGIS Server environment. This factor often makes debugging difficult. Below I have made an expanding list of issues related to cahcing as well as the various cache levels to clear when debugging.

Issues related to caching: query does not return correct field as defined in 'outFields' query property

Cache Levels

1. AGS web service cache, this can be cleared by restarting the AGS web service from ArcCatalog or by web admin interface
2. Tile cache, cleared by 'deleting cache', and then reconfiguring tile cache within service properties of the web service
3. Web browser cache, cleared by clearing cache of web browser
4. REST API cache, cleared by going to http://yourserveraddress/ArcGIS/rest/admin/cache and clearing cache manually
5. KML cache, if using a Google hosted KML with your application, to have this load dynamically you need to add a random number to the end of your kml address ... google it!