9 out of 10 maps won't load

[fourhappyrivers]

Not unlike my other post, but this is pretty frustrating. I've downloaded about 20 maps today and none of them have opened past their first page with the image and credits.
What the heck am I doing wrong? It's not like it's rocket science to drag the .iwd file to my main folder.
Is there some setting I'm missing? Is this a Mac thing? I'm going nuts here, can anyone help!

[Dark Saint]

So all maps you have tried, will not work at all ?
where are you getting them ?
Have you read the read me's ?
Sometimes maps give new textures which you may be required to up your placed ram that is dedicated to the game, for them to function.

[fourhappyrivers]

I'm downloading from callofduty.filefront.com. And every once and awhile a map will work. I have, maybe 6 that are working out of the 40 or so I've downloaded and tried. I'll see if I can figure out how to up the ram for the game.
Thanks for getting back to me. This is really frustrating...