Primefaces modal dialog blocker inside frame - z-index ignored (IE 9)

[greeraply]

I have PrimeFaces (version 3.4) application finished and tested. The problem is, that in production environment it is launched in enterprise portal, which is placing application inside frameset.The additional complication is, that on client machines, IE settings are forcing compatibility mode. We overriding that settings by headers. Now our application is forcing IE9 mode within its frame, but the whole frameset is using compatibility mode. A madness, but the application really works as if it was run separatly without compatibility mode.As for yet, the only thing we've catched for not working, is the modality of the dialogs. It is done within PrimeFaces by div, with position fixed, width and high of the viewport and high z-index (over 1000), but lower than the z-index of the dialog.IE developer tools are showing, that this div has the size of the whole viewport - it occupies the whole frame. The problem is, that it is not blocking click within application. When run without frameset, everything works as expected.What can cause the problem? Is it the bug with IE z-index in frames? Or something else?