"However, the operation failed when the rubber stamp on those cards intended for the city of Hamburg misspelled Hansastadt as Hanfastadt. Apparently, German is difficult language."
The mistake was probably made by confusing one of the two variants of 's' that were used back then with a 'f':
The one that looks like an f was only used at the beginning of words, also within compound nouns.
In this example, one would read as "guardroom", the other as "wax tube"
http://de.wikipedia.org/wiki/Datei:Wachstube.svg
Funnily enough, it's actually "Hansestadt".
http://en.wikipedia.org/wiki/Hamburg