Am I missing something obvious? Any time I'm in a dungeon, hitting M just shows me the macro-map of aboveground Ancaria; zooming in gives me a black square. I can see maps in walkthroughs... how can I display them?

Tab key will bring up the mini-map. It doesn't show as much as the overworld map, but at least it's something.

I don't get anything from Tab. I haven't changed any of the default keyboard configs, so I'm not sure why I'm not getting the mini-map. It's not killing the game for me or anything -- the visual walkthrough has dungeons fairly well mapped out -- but it's odd.

Make sure you are holding tab down, the mini map only stays up while the key is pressed.

No, Tab's never given me anything. If I press M while I'm in a dungeon, I see an overland map of Ancaria, often quite distant from my current location in the dungeon. Pressing Tab does nothing, clicking to zoom in just shows black space.

I've seen the occasional but rare bug since buying the game, but if this is happening a lot, something's definitely wrong. If you don't see a map on entering the zone, that's normal because you haven't uncovered anything yet; but if you've cleared the dungeon and still don't see a map when you hit TAB, that's a fo realz bug.

Super weird -- I'm running it in XP and have perfect performance other than this one issue. I'm just soldiering through using maps posted on the Sacred fan sites instead of "doing my own mapping," but that's ... really really odd.