I believe I have the fix as I was also having problems.
1. Install Java from their download page
2. After install reboot (not sure if it's necessary but I did anyway)
3. Go to Control Panel (expanded view) and you'll see a Java (32bit) icon.
4. Click on Icon and Java Control Panel will open.
5. Click Advanced Tab
6. Click + sign For Java Plug-in
7. Uncheck Box that says Enable Next Generation plug in.
8. Close your browser (if it was open). I think I rebooted here, too..probably not necessary.
9. Go to the Java Test Page
and click the version link at top of page.
10. You should see a pink box (I did) with version you have installed.
I also found this blog
that shows why Java might not be working on x64 Vista and how to fix it....I am certain it applies for x64 Windows 7 as well.