You could do this..
In the <head> section create a function to generate a popup rather than have a massive chunk of code in the link itself.. such as:
CODE
function launchPopup(url){
window.open(url, 'popup', 'width=500, height=500, scrollbars=no, resizable=no, toolbar=no, directories=no, location=no, menubar=no, status=no, left=0, top=0');
}
Now for the link.. far less cumbersome:
CODE
<a href="http://www.yourweblog.com/yourfile.html" onclick="launchPopup('http://www.yourweblog.com/yourPOPUPfile.html')">About</a>
Notice i removed the "return false" from the link, as that would disable the original link from loading the "yourfile.html".
This is all assuming that i have correctly understood you and you want both the main page to change AND for a popup to be generated?
Other stuff you could now do with this would be to allow the function to take more parameters, for instance you may want to define the width and height within the link tag so if you had multiple link instances requiring a popup they could be easily made to vary. Also you could have the function find out the visitors screen size and then using the width/height values sent it could load create the popup in the center of their screen?
Hope this was useful in some way
P.S: Popups are horrible! ...just needed to get that off my chest..