The first time I arrived at the site (using Firefox) it had the missing plugin icon. I tried to do Firefox's plugin installation, but as usual it didn't work and offered a manual install. So I did the manual install the restarted the browser. When it started, it said something about needing to load something or install something, but I don't remember what it said.
When I load the page, the flash object shows an Adobe Shockwave placeholder image and I get the message, "Missing shockwave Decompression XTRA".
Clicking the "Get Shockwave Essentials" link below the flsh object took me back to your install page. I tried to reinstall, but I got a message saying the system had to be rebooted and I should do that and then try the install. So I rebooted, went back to the install page, ran the install program again and got the same message about rebooting.