When Superman first appeared in comics he worked for The Daily Star (first refereed to in Action Comics #7, Dec 1938 ). Then in the 1940s that all changed, without any in-story explanation and during a multi-issue story line, the paper had suddenly become The Daily Planet.
According to Wikipedia:
the fictional newspaper's name was changed to avoid a name conflict with actual papers that had "Star" in their titles.
This explanation seems a little... lame (for lack of a better word), especially as Superman co-creator Joe Shuster named the Daily Star after his hometown's Toronto Daily Star which he related to be 'a great influence on his life.'
Does anyone know anything further about this change, perhaps gleamed from a biography or other historical text on comics in general or Superman in specific?