Why can't I download anything from the Mac App Store?

Hello there,

I just toped up a $50 iTunes card and have the money ready to spend on apps and music now.

This morning I went into the Mac App Store and wanted to download the free kindle app, the app icon dropped onto the dock and downloaded, the a message came up saying that there was an error :

The application could not be downloaded.

An error occured while extracting files from the

package "mzm.budfbxul.pkg".

Cancel Retry

(retry doesn't work either)

the same thing happend to all other apps I tried to install some what do I do?

I can't install any apps although I meet the requirements.

Is it the mac or something else?