opening popup causes the browser window looses focus on IE9

opening popup causes the browser window looses focus on IE9

In the example of the DIALOG implemented with a POPUP  ( here) starting from the second time the dialog is opened the browser window looses focus and becomes the last one in the windows stack. This happens on IE9 in windows 7. The problem doesnt appear on other browsers(Chrome, Firefox, Opera) . 
I implemented a similar example (popup that cannot be dismissed and header + content data-role within the popup) and also my example has the same problem.
I know IE9 is not a target, but this might be a symptom of a bug that other browsers are able to correct automatically (now....). Often IE9 causes this problem because of blur events triggered artificially by  js code when no dom element has the focus but also when the environment becomse "dirty" because of some wrong operation performed on the dom..