Internet Explorer won't display Zoomify when displaying Zoomify in Jquery UI Tab [#1168276]

I have this strangest error and I finally know where it's coming from, but don't know how to solve it.

If you look at http://www.horsmanprojecten.nl/test/projecten/nijverheidsstraat with any version of Internet Explorer (i.e. 7,8 or even 9) you can see the problem;

The page loads with the first tab on the left ("Projectinfo & Ligging") openend. I put the Zoomify in there and as you can see it is working as expected. If you click on the tab "Situatie & Woningtypes (the tab where I want the zoomify to show up), then you'll only see the Zoomify Flash applet, but without any pictures loaded. It doesn't give an error though. In Firefox, Chrome and Safari the applet is displayed as it should.

I did a little digging, but all I could find is this issue: #463532: zoomify with thickbox The solution provided there for refreshing IE dind't work for me though.

Does anyone have an idea / solution for where this is coming from?