Ok, I have spent a while on this problem and this is what I have gathered:
If you make an AJAX call in IE7 and you have a window.onbeforeunload function spe
Sid_M said a valid point, with that design of browser we have to design our application accordingly.
Why to go for anchor tag & href for popup windows, just use onclick method in label or even td tag and call window.open
Simple example from one of my application
How it works