Some Icon Downloading Trouble

Some Icon Downloading Trouble

I have been browsing many of the Icons and downloading quite a bunch of them, but I have run into a problem with many of the icons I have downloaded. Most of them turn out okay but with a few when I open the folders they are empty but the folder size is the same as it describes on the site. Whats wrong with this?
Please assist thanks.

Try using a different extracting program such as WinRAR, WinAce or WinZip.

Thx alot, it worked now I can go back to a downloading frenzy