im having the same problem.. any solutions yet?

Fatal error: Uncaught exception 'Exception' with message 'String could not be parsed as XML' in /home/drupal_base/sites/all/modules/ubercart-DRUPAL-6--2/payment/uc_google_checkout/uc_google_checkout.pages.inc:30 Stack trace: #0 /home/drupal_base/sites/all/modules/ubercart-DRUPAL-6--2/payment/uc_google_checkout/uc_google_checkout.pages.inc(30): SimpleXMLElement->__construct('') #1 [internal function]: uc_google_checkout_callback() #2 /home/drupal_base/includes/menu.inc(348): call_user_func_array('uc_google_check...', Array) #3 /home/drupal_base/index.php(18): menu_execute_active_handler() #4 /home/xcube/public_html/index.php(3): include('/home/drupal_ba...') #5 {main} thrown in /home/drupal_base/sites/all/modules/ubercart-DRUPAL-6--2/payment/uc_google_checkout/uc_google_checkout.pages.inc on line 30

On line 30 of that .inc page is: $xml = new SimpleXMLElement($input);

I printed out whatever was causing the problem in $input and it displays this:

Queries taking longer than 5 ms and queries executed more than once, are highlighted.
ms
#
where
query