Guvwenea -
I had the exact same problem. Go to the website listed above, and download the maps. I download one at a time, you should be able to do this as well if you get the one big zip with all the maps in it.
The maps will have a name which ends in a _1, _2, etc. Rename them and get rid of it. So you start off with Blackburrow_1.txt, rename it to Blackburrow.txt.
Put the maps in you EQ maps directory. You should see them next time you zone, or log in, it varies for me.
The _1 and _2, etcetera, refer to the layer control on the backspace map window. You can apparently have several maps of the same thing on top of one another, and view them by hitting the 1,2,3 buttons. If you already dumped a ton of maps in your folder try pressing the 1 button, you might see the maps.
Also, the map may be "disappearing" on you because the height filter is on, press that button and you might see the maps.
Good luck :)