The demo site does NOT display the PDFs like they are supposed if I have another tab with our picture gallery trying to display one of our PDFs. If I close our Gallery Server website and just have your DEMO site open then it displays fine. This is on the same computer that took those screen shots. The version Adobe that is on the computer is Acrobat 9 Pro 9.4.6 on browser FireFox 7.0.1.
ALL three of the browsers are on the same machine.
In IE9 it won't show the pdf like above but if you click on "Enlarge PDF to fit browser windows" it doesn't show in the enlarged state but when you click the browsers back button then the PDF appears in the embedded window.
In Firefox the above doesn't work it just displays the blank window like in the screen shots.
It seems like once we get the error below (which takes about 5 min before it appears) and you click on the ok then the PDFs appear like it does in the Google Chrome browser (but not always).

I am wondering if it could be an Adobe version issue.