New Post: "Cannot complete this action" when provisioning a ListInstance from a ListTemplate

When I try to provision a new list instance, from a template which I've previously extracted with SPSource (latest version) I get the following exception:

Cannot complete this action.

Please try again.   at Microsoft.SharePoint.Library.SPRequestInternalClass.UpdateField(String bstrUrl, String bstrListName, String bstrXML)
   at Microsoft.SharePoint.Library.SPRequest.UpdateField(String bstrUrl, String bstrListName, String bstrXML)

If I create a new standard Custom List and add the content type to it, it works fine.

Any thoughts?

Shaun O'Callaghan