Do they open correctly on a different computer? Could it be that your IE is corrupted (as we all know how easily that happens)?

That's exactly the problem. They open fine on other machines! Grrrrrr.

I encountered exactly the same problem when trying to develop a web page that utilised pop-up Javascript windows...

When one opens an html page using the Javascript (window.open) command, Firewalls or Ad removing software will insert a line of code on to the page that gets saved to your temporary internet files folder. So when you revisit the page, even with the software turned off - it will open blank because the line of code is still saved in your temp file.

Disabling anti-pop up software or firewalls THEN deleting your internet cache will solve the problem, but the code will re-insert itself when the software is turned back on.

If you are looking to get round the problem and still want to use the (window.open) command without having to worry about the code insertion, then use a frame table inside the pop up window (a page using frames). Firewalls and ad removing software will not lay the same code on any pages the pop-up calls up, so a frame table gets rid of the problem.

Sorry if this isn't very clear, I'm tired