Disappearing Pages and Posts

Here´s a headscratcher…

We´ve run our site for almost three years with no issues until about a week ago the pages/posts started disappearing after loading. In Firefox and Chrome our homepage loads fine, but pages and posts load for a split second, then disappear. We didn´t make any changes to the site or CSS and all was fine…until it wasn´t.

Internet Explorer loads it with errors, generally a jquery syntax error. What has happened? Anyone know how to fix this?

Check out our site´s working homepage or a malfunctioning page such as this one. Watch the screen closely in Firefox or Chrome as it will load briefly, then disappear.

PLEASE HELP!