pop up window from irctc site comes inspite of it being blocked in firefox preferences what to do to stop advertisement from popping up

[Tapas Mishra]

While browsing following page
http://www.indianrail.gov.in/
I get a random window popped up on my box
the link which pops up is of following page
http://n.admagnet.net/panda/www/delivery/ac.php?BAYGBw8ZBQlTXUFFQ0tSDxkZHRAeRk9FTk2m09bByMrFzLW6sru%2Bq%2Fru4vb356nK9Pv59%2FG96%2FTq99TE2teZlYDUx9zYyMmQiNvZ3NfcwcGLh57azouBm87QsLSy%2FvTjtaSy9Pg%3D

In case any one wants to see what I am trying to tell just open that
page and try to click on some menu button in navigation bar.
You will see an advertisement "Play online games"

Now I would like to tell
Firefox-->Edit-->Preferences-->Content-->Block Pop up windows
there is a tick on that box.
Also as I open that page
http://www.indianrail.gov.in/
I do see a message in firefox which says this page tried to open pop
up windows which have been blocked.
And inspite of this message I get to see that advertisement of
"playing online games"
It has been so frustrating and annoying to each time close that pop up.
My question is inspite of the option of blocking pop up windows
enabled why do I get to see this advertisement.
Can I some how stop this behavior.
I use Lucid 64 bit and Firefox 3.6.10