As described here, Internet Explorer can download ZIP files incorrectly (it essentially ends up compressing the file twice and corrupting it). This problem does not occur with Firefox.

This WinZip help guide recommends unchecking the IE HTTP 1.1 settings (Internet Options > Advanced) and clearing the IE Temporary Internet Files (Internet Options > General > Delete). I've confirmed that it works using XP SP2 and IE 8.

I've also made the Twelve Kingdoms zip files available via another service.

Shadow of the Moon
A Thousand Leagues of Wind
The Shore in Twilight
Dreaming of Paradise

Labels: 12 kingdoms, computers