Why I have no trees in my assets?

I’ve clicked “Assets > Import Package > terrain assets” but when I create a new terrain and click on “add tree” under the tree paint menu, this is what I see:

Really? Do I have just a palm?

Thanks!

edit: can’t upload screenshot. As I click “accept” on “Preview and resize” nothing happens. Here’s a link instead: http://s10.postimage.org/3zro69487/Schermata_2012_11_02_a_13_15_29.png

Just re-downloaded the terrain asset from the assets store and got all the different trees. For some reasons, the one included with Unity just has the palm, not to mention the one you can download from the website: the download never gets completed, which means Unity will throw errors when trying to import.