When I build a CCK nodefield and insert default behaviour, I suspect this default behaviour is inherited in every node instance I make from this nodetype, right?
If this is espected behaviour there is a bug in the module.
When I edit a node, and click on pollfield, I see a clean pollfield with not any default setting set in the Nodetype CCK_field settings (admin/content/types). Also The question field is blank in the node, while on the nodetype I filled in a question title.
Preferred behaviour is having a default question in a pollfield on nodetype basis, and if you want for some reason another question on a specific node, than change this on node level.
Thanks for going into this!