IE 7- Popup timer does not start until session tab is clicked on

I am getting a strange problem with IE7 tabs.

The web application I am working (developed in ASP.Net, .Net 2.0), will show
a popup message with the count down timer 2 minutes before session time out.
The count down timer on popup will start with 120 and will be count down to 0
and if the user doesn't click on the Continue button (which is on popup),
application logs out and the web page will be shown with login page. If the
user clicks Continue button it extends the session for 20 more minutes.

Now the problem is, I have two tabs (or more tabs) on my IE7. One tab with
my application website and the other tab with xxxxx.com website and xxxxx.com
is active now. My website will not show the count down timer popup till it
gets activated. Once the application tab is actived even after 2 hours or two
days, then it starts the count down timer, till that time the session is
active. (That means somebody can keep the application session live for any
long time by opening one more tab besides it and new tab is active tab.)

So if my application is opened 2 hours ago and it is hidden by other tab, it
will not time out till I make the application tab as active tab. Once I make
the application tab active after 2 hours or 2 days it shows the count down
timer popup on which I can click on Continue to extend the session.

Can anybody know how to stop this behaviour. I can't remove the popup as per
the business.

Thanks in advance and any help will be greatly appricated.

Re: IE 7- Popup timer does not start until session tab is clicked on

How are you implementing the timer? Is it triggered by an onload
event? What is the event attached to? (body,etc)

Re: IE 7- Popup timer does not start until session tab is clicked

We will have following startup script on all the pages.