1. SQL XML accepts even XML fragments; i.e., there does not need to be a root element for SQL to process it. Since you have indicated that you have "proper parent element", I am assuming that you have a root element.
2. Simplify your problem to a very simple XML document, perhaps with a root node and one element under it and see if you can process that through SSIS successfully.
3. If neither of the above helps, as Cooper suggested, post a representative sample of your XML.