Tonight, out of the blue, my web site (www.tenerahome.com) started acting very strange.

The front page loads without any problems, but when I try to click on any link, I get a "404 Not Found" error. The admin section works fine.

Any ideas what may have caused this? I contacted my hosting company to find out if they've made any changes to the servers.

The only change I've made in the last 24 hours was slightly modifying my .htaccess file to ban an IP address, but reverting to the previous settings didn't help either.

Any help would be very much appreciated!