urgent help needed in checkout

[DrByte]

<?php
  foreach($payment_modules->modules as $pm_code => $pm) {
    if(substr($pm, 0, strrpos($pm, '.')) == 'googlecheckout') {
      unset($payment_modules->modules[$pm_code]);
    }
  }

 line 123      <?php
  foreach($payment_modules->modules as $pm_code => $pm) {
    if(substr($pm, 0, strrpos($pm, '.')) == 'googlecheckout') {
      unset($payment_modules->modules[$pm_code]);
    }
  }
  $selection = $payment_modules->selection();

  if (sizeof($selection) > 1) {

Notice how you've got code repeated before line 123?
You should remove that repeated code.