After doing a LOT of module enables/disables to find what was causing the 'Error Requesting Data' message, I found it is the Global Redirect module that is somehow interfering with the Live comment preview. Working to see if there can be anything done...
Comments
Comment #1
Gurpartap Singh commentedglobal redirect module was treated to not cause problems of this post anymore. in other words, it now doesnt redirect page requests when there's a form request using post method.
you should get the latest version of global redirect module to get rid of the problem. he it persists, open the existing issue in global's issue queue.
Comment #2
dave reidThere hasn't been an updated Drupal 6 release of the Global Redirect module since 2007-Dec-30.
Comment #3
Gurpartap Singh commentedIt has been fixed with this commit for Drupal 5: http://drupal.org/cvs?commit=125132
But I have reopened the original issue to port the patch to Drupal 6: http://drupal.org/node/226031
Please follow up there :)