Cannot download *.zip file from link on web page

When I click on a link on a web page which refers to a zip file then the zip archive is not
downloaded as usual (on other WinXP systems).

Instead an error page appears:

The XML page cannot be displayed
Cannot view XML input using style sheet.
Please correct the error and then click the Refresh button, or try again later.
An invalid character was found in text content.
Error processing resource 'http://www.aaa.net/data/test.zip...


So why does this not work on this computer while it works on others?

It seems to me that IntExp 6 hast lost the info "Download everything whose URL ends with a ".zip" extension"

How can I re-tell this IntExp ?

Lorenzo