Maybe a stupid question but it's not just the font size settings in Firefox is it?
I thought so at first too, but I haven't messed with the settings, and it flips back and forth fairly regularly in the same Firefox window without me having to do anything but reload the page.

i've just taken a ...

Hi,
I've just started using Serendipity, really good tool, wish I'd found it sooner.
I'm having some trouble with the appearance of my site in Firefox under linux (not sure about Mac or Win browsers, but it works fine in Konqueror):
http://drspirograph.com/

I've customised the theme somewhat, but ...