I'm using <link rel="stylesheet" type="text/css" href="style.css" /> but using <link rel="stylesheet" type="text/css" href="style.css?v=123" /> and following your suggestion solves the problem. Except I have to increment the ?v=123 for each and every preview of course...
Sorry, forgot to say that I usually click on Preview at the bottom
left of the HTML-Tools window. Pressing F12 and CTRL-F12 don't work
either. Neither does pressing F12 twice.
Extended preview does, however, and both the HTML-Tools preview, and
the preview in the browser, update correctly when F12 is pressed.
Thank you for checking out the different options and letting me know how
they went. It's interesting that caching isn't an issue when you use
Extended preview in either external or internal preview. This helps with