You've presented the browser with an incomplete layout problem. You have a three-by-three grid, none of whose columns or rows have fixed sizes. So the issue is you end up with a taller first row than you intended, as the browser tries to allocate ‘spare’ height caused by the rowspan in the second column amongst the cells in the first column.
There isn't a standardised algorithm for this; browsers do different things, often including unpleasant things like looking at the raw number of bytes of markup in each cell. You don't want to rely on this behaviour. It also slows page rendering down and can give really weird, page-distorting effects when there's a very small or large amount of content. If you need to use tables for layout, make sure to use table-layout: fixed with explicit widths for the fixed-size columns, and set explicit heights for cells when there are rowspans, to avoid ambiguity.
But a proliferation of rowspan/colspan is often a hint you should be looking at a different form of layout. This example is very much easier to acheive using CSS instead. eg.:
<div id="ads">
<script type="text/javascript">//...google stuff...</script>
...
</div>
<div id="content">
<div id="video"><fieldset>
<legend>...</legend>
<object ...>
</fieldset></div>
<form id="poll" method="post" action="..."><fieldset>
<legend>...</legend>
...options...
</fieldset></form>
<form id="subscribe" method="post" action="..."><fieldset>
<legend>...</legend>
...fields...
</fieldset></form>
<div id="about">
...
</div>
</div>
with styles something like:
#ads { position: absolute; right: 0; width: 160px; }
#content { margin-right: 160px; }
#video { float: right; width: 440px; }
#poll, #subscribe { margin: 0 440px 0 0; }
#about { clear: right; }
I'd also advise you to move the JavaScript logic out from the inline event handler attributes you currently have to separate JavaScript blocks (either embedded <script> blocks or linked external scripts). Especially for the multi-line event handlers: quite apart from the horrible maintainability of mixing scripts into markup, in HTML/XML newlines in attributes are not preserved. That means your newlines in JS code are converted into spaces, so if you miss a single semicolon your script will break or behave oddly (where usually in a script block or external script, the auto-newline-semicolon-fallback would save you).
ie.
onsubmit="
var inputs = this.getElementsByTagName('input');
var checkedValue;
for(var i = 0; i < inputs.length; i++)
{
if(inputs[i].getAttribute('type') == 'radio' && inputs[i].checked)
{
checkedValue = inputs[i].value;
}
}
/*makeAjaxPostRequest('/poll/ajax-vote.php', 'vote='+checkedValue, processAjaxResponse);*/
makeAjaxGetRequest('/poll/ajax-vote.php?vote='+checkedValue, processAjaxResponse);
return false;"
instead:
<form id="pollForm" method="post" action="/poll/form-vote.php>
...
</form>
<script type="text/javascript">
document.getElementById('pollForm').onsubmit= function() {
var checkedValue= getRadioValue(this.elements.vote);
makeAjaxPostRequest('/poll/ajax-vote.php', 'vote='+encodeURIComponent(checkedValue), processAjaxResponse);
return false;
};
function getRadioValue(fields) {
for (var i= fields.length; i-->0;)
if (fields[i].checked)
return fields.value;
return '';
};
</script>
Always allow only POST requests for active forms that do something positive. Always use encodeURIComponent when creating query strings. Don't use getAttribute as it doesn't work right in IE; use direct DOM Level 1 HTML properties instead, eg. input.type.