Unable to import orders. increment_id Error

[David]

Connector for 6.1 (revision 152). Prestahop 1.5.5.1

I'm getting this error when I try to import orders. It's possible that this mapping doesn't exist?

2014-03-31 13:04:15,395 7949 ERROR ? MERCATO-BIG: 'increment_id'
Traceback (most recent call last):
  File "/opt/openerp-ocb/server_launch/openerp/addons/base_external_referentials/decorator.py", line 130, in wrapper
    response = func(self, import_cr, uid, external_session, resource, *args, **kwargs)
  File "/opt/openerp-ocb/server_launch/openerp/addons/base_sale_multichannels/sale.py", line 603, in _record_one_external_resource
    order_mapping=mapping[mapping_id], defaults=defaults, context=context)
  File "/opt/openerp-ocb/server_launch/openerp/addons/base_sale_multichannels/sale.py", line 589, in check_if_order_exist
    order_name = '%s%s' %(shop.order_prefix, resource['increment_id'])
KeyError: 'increment_id'