Notice: Trying to get property of non-object in workbench_moderation_node_update()

Hi
In same case when programmatically create nodes we have these notice and warning logged in errors log and some time displayed on the front end site:
Notice: Trying to get property of non-object in workbench_moderation_node_update() (line 677 of /home/XXX/modules/workbench_moderation/workbench_moderation.module).

Notice: Undefined property: stdClass::$original in workbench_moderation_node_update() (line 677 of /home/XXX/modules/workbench_moderation/workbench_moderation.module).

Notice: Trying to get property of non-object in workbench_moderation_node_update() (line 673 of /home/XXX/modules/workbench_moderation/workbench_moderation.module).
in Line 677

Notice: Undefined property: stdClass::$original in workbench_moderation_node_update() (line 673 of /home/XXX/modules/workbench_moderation/workbench_moderation.module).