Since 1.4.2, whenever I create a map, it creates a blank item with the proper map name. However, when I go to activate it, it will display an area on the map which is almost completely visible already, giving it the appearance that instead of a 1:1 ratio, it's showing a map with a 16:1 ratio (or greater). A fresh install with no texture packs running produces the same effect (though I used the same world as the old install within the new install, if that makes a difference).

Posting on the general forums has given me no feedback on how to fix this, and it wasn't addressed in the latest bug fix patch 1.4.4.