Looking through your page source code, I'll try to do some guesswork and help you with this.
Open the file templates/rhuk_solarflare_ii/index.php and look for the code below:
<div id="left_outer">
<div id="left_inner">
<?php mosLoadModules ( 'left', -2 ); ?>
</div>
</div>
Change the above code to
<?php if (mosCountModules( 'left' )) { ?>
<div id="left_outer">
<div id="left_inner">
<?php mosLoadModules ( 'left', -2 ); ?>
</div>
</div>
<?php } ?>
What the above code does basically to load the whole of the left section
only if there are modules published in the "left" module space.
Note:
<?php mosLoadModules ( 'left', -2 ); ?>
could be
<?php mosLoadModules ( 'left', -1 ); ?>
or
<?php mosLoadModules ( 'left' ); ?>