Noticed there was an update so I clicked the tab labeled "DHTML Menu" tab, then clicked the dropdown tab labeled "Menu Version Information, and the page opens, but with this Windows Internet Explorer dialog box.
I have gone to other web site that use .php and do not have any problems opening them
Much as I hate to admit it, I'm seeing it, too. IE7/XP Pro.
Most of the page is actually there behind the error dialogue (center column, but not the right column - Buy Now, Download, Menu Users, etc.). However, when you OK out of the dialogue the Milonic page goes away completely and is replaced by the typical 'IE cannot display the webpage...'.