Strange Outlook Express Problem

For the second time in the last 6 months, my Outlook Express has, out of the blue, refused to allow me to click on links in my emails. When I do, nothing happens. This happened about 6 months ago. I couldn’t find anything wrong and, of course, Microsoft help site was no help. Then just as suddenly as the problem started, it quit and the links started working again.

Now it is doing it again. Any wild guesses as to what the culprit is?

Incidently, links on web pages work just fine.