IE10 Metro opens a small window as maximized on Windows 8 machine

Hi,

I have a window created using calendar = window.open('url','winName','dependent=yes,width=250,height=270,screenX=200,screenY=300,titlebar=yes') that opens up a popup window size (small size window) in IE8, IE10Desktop and all other browsers but in IE10 Metro on Windows8 OS, it opens up as a maximized window with the actual content taking a small space at the left hand corner side.

Similarly the alert("Hi"); takes up the whole window and does not get displayed as a popup.

Is it the expected behaviour ? Can I do something in my code to correct it? I tried with fullscreen=no and theatermode=no

Thanks,

SJ