Provision to bypass form token validation to avoid getting "Form is outdated" validation error.

Hi,
I have a multistep node form.
Half way through the form through a popup dialog user is asked to login if they have not logged in prior.

Upon successful login when proceeding with next page of the node form, I get this validation error:
"The form has become outdated. Copy any unsaved work in the form below and then reload this page."

I understand its because of drupal_validation_form() check for $form['#token'] and
$form_state['values']['form_token'] not being same.

But this is a specific use case wherein I want the user to have a feeler of our business feature.
How can I achieve this?. Any support on this front?

Thanks.