Javascript window.open problem ("Error on page") in SP2

I have a Dell Dimension 8250 running XP Home (including, as it was delivered, SP1).  Recently I installed SP2 and discovered that I had a problem in IE, whereby it would not open a new window via window.open in Javascript.  I can, however, open a new window where a URL is provided on the page, by right clicking and selecting Open in New Window.  So the problem seems to be with Javascript and its interaction with SP2.  A typical example of where the problem occurs is trying to use the Print View button when viewing a message in Hotmail.

I uninstalled SP2 and the problem went away.  I reinstalled SP2 and it came back.

I have ensured that pop-up blockers are turned off and also checked to make sure that Active Scripting is enabled within the Security Options in IE.

I tried the advice at http://support.microsoft.com/default.aspx?scid=kb;EN-US;Q281679 but this did not seem to help.

In order to try and test the problem further I wrote a small HTML script with the intention of using it to trace the registry activity with REGMON both with and without SP2 and then comparing the results.  The script is as follows (I am absolutely no expert in Javascript, by the way):

Hi Robin

I then had a small HTML script called page2.html (in the same directory) which simply puts out another message.

When I prepared these scripts on my laptop (a Dell Latitude D600 running Windows 2000) they worked fine.

When I transferred them to my XP machine they failed even without SP2 installed, leaving me well and truly baffled.  The page1 script executes and puts out the "Hi Robin" screen but then does not open page2.html but rather gives the sort of 'close door' sound.

I confess I am stumped and would welcome any suggestions.