While reading on pre-WWII Nazi Germany, we found information that stated that (not surprisingly) Hitler ordered that all books he found to be anti-German were to be burned. Of course, this included all Jewish authors such as Freud, and Helen Keller (probably because he had no use for people with disabilities), but we could not understand why he had Hemingway's books burned...

...anyone have an insight to this curiosity??

http://www.ernest.hemingway.com/journeystowar.htm

This does not discuss Hitler having Hemingway's books burned. But it does discuss Hemingway's background concerning war and his writings. So perhaps Hitler took offense to what Hemingway had written.

I don't know if he had Hemingway's books burned but he could well have because of events during the Spanish Civil War.
The war between those who supported the left-wing Popular Front in Spain and those who supported the right-wing National Front is often seen as having been a "dress rehearsal" for World War II, with Hitler backing one side and Stalin backing the other. Stalin's side lost the actual war, but won the propaganda war, not least because it was supported by an international clique of writers and intellectuals, including Ernest Hemingway.