The site loads fine for me on broadband.
As you've used CSS to layout the page, what I think you're seeing is a brief moment when the HTML has downloaded but the CSS hasn't, once the browser reads the CSS the page jumps into position.
You could try changing the way you pull the style sheet in, to:
<link href="http://www.sbjewellery.co.uk/html/css/template.css" rel="stylesheet" media="screen">
I seem to remember reading that some versions of IE are slow with @import.
On the subject of CSS you should move all your style information to the external CSS file.
You are also missing the DOCTYPE and a pass through
http://validator.w3.org would help fix the errors in the page, these could even be contributing to the problem.
SBJewellery
Linear Mode
