which theme you use?
for mobile themes it's better to switch off the panels (left/right) and also it's a good idee to make blocks specific for a mobile theme.
to switch off blocks in a panel, use the Dynamic visibility options settings and select the theme on Show or Hide the block on theme.
also you can modify the theme index.template.php and insert the lines:
$modSettings['pmx_paneloff'] = array('left', 'right');
after the lines:
global $context, $settings, $options, $txt;