CSS & Text Resizing

I have done some work on a page which has different items such as a table which has to have a grey background and a header that has to be red and big - however, I find that in IE and Firefox, when you resize the text, the fonts increase ... Can you prevent this from happening.

I have it working on one page as a DIV but then other items within the region fial to comply with the overall CSS.

Whats the difference between saying ??
<div class="mystyle>...</div>
and
<p class="mystyle>...</p>

Anyone ????

Font/text resizing is an acessibility feature. Get used to it. Trying to disable it will only annoy users.

A <div> is a generic container and may contain other block level elements.
A <p> is a paragraph and may only contain inline level elements.

http://www.cs.tut.fi/~jkorpela/html/nesting.html

You don't want to design a page that looks good at your screen resolution and text size settings. (unfortunately too many sites are designed this way). You can design the page so that it's "fluid". That is, the page elements will be in different places at different resolutions. You can also design "elastic" pages. That is, the page elements will shrink and expand to fit the viewport size. Thus the page will not be rendered "identically the same", but should look "suitably the same".
I like to use h tags and percentages so that larger text will always be larger in relation to other text no matter what resolution or text size setting is used.
Try a test page using a main head at the top of the page, a floating left nav/ad div, and a right content div with sub-heads, and a bottom clear both footer. You will see what I mean.
BTW Tables are notorious troublemakers to page rendering when they're used to structure page layout. You should only use them to display tabular data.

I think the biggest issue designers have is letting go of the fact that their page *might* look different in different browsers on different platforms. Sometimes you have to give up a little to get a lot... think about the accessibility and the chance to present your page to all kinds of users...

How would your page display on a cell phone/pda? How would it look on a screen with resolution different than yours? How would it look with the font size increased? All of these things are out of your control, but a good solid design can prepare for this.

As for the difference between DIV and P?
I always see it as two main ideas:
Visually: By default, a paragraph tag has added spacing between elements.
Symantecally: Paragraph tag is just that, a paragraph of text... a DIV is more of a container.