Hey Tom,
Does Iress bring up another Firefox window when you click on the link? If so then it wont be a pop up problem.
To check if its on the allowed list on Firefox:
Tools > Options > Content > See the pop-ups heading then click on "Exceptions"
Scroll down and you should find
http://www2.commsec.com.au. - "Allow"
If you still cant get it to work try re installing Java
If still not working good luck you're on your own
