Save as webpage + SVG = trouble

I am having trouble when saving a Visio file as html. The Visio file contains
50-something pages; the “front page� is a world map with spots to click,
which brings you to one of the other pages. So far so good.

I want to save images as .svg (the zoom-function is nice!), and in the first
versions of my project it worked fine. But then, after a while (adding new
pages etc); when I opened the html file I got a message saying “This page
requires an SVG viewer�.

I can still open an early project version, and get nice svg graphics; so
it’s not that my IE is missing a svg viewer.

What’s going on? What should I do? (btw I’m using Visio 2003 standard).

Any hints or help is greatly appreciated!