All theme examples on the settings page have a naked slot number variable, should be quoted

Puzzling over why my adsense ads aren't being displayed properly after adding the suggested code to my node template I noticed the ad slot differed from both what I'd entered and what google code looked like.

All the examples using php (for both blocks and themes) on example.com/admin/settings/adsense all suggest code like this:

if (module_exists('adsense')) {
  print adsense_display(array('format' => '468x60', 'slot' => 0123456789));
}

The slot number needs to be quoted in order to get the markup to match google supplied code:

if (module_exists('adsense')) {
  print adsense_display(array('format' => '468x60', 'slot' => '0123456789'));
}