I'm really mystified about this. I published the standard (unmodified) sample (it was page 2 of the Beta template) but that doesn't exhibit the crashing problem, so it's obviously something to do with my changes. Here's how I changed the original sample:-
1) Resized the page a bit, to fit my own logos.
2) Removed the top row of buttons.
3) Replaced the standard logos with my own.
4) Removed the top 2 buttons from the left-hand set.
5) Made the 3rd button (which is now the top button) link to a pre-existing page.
6) Changed a few colours.
7) Removed a small hyperlink text (that was linking to Xara.com).
Can anyone see anything there that could result in the strange crashing problem? If not I guess I'll have to do each stage, one at a time until the problem resurfaces.