Sitecore item will not go into edit mode; any suggestions on how to troubleshoot?

Question

I have several Sitecore items (whose template is connected to an approval workflow) that will not go into Edit mode when clicking "Edit" from the "Review" tab. The same workflow is used elsewhere on the site successfully (the site is more than 3 years old), but clicking Edit in this case doesn't seem to affect the workflow state.

I've turned on verbose logging, which provides a lot of detail, but nothing to indicate any error conditions. I've been comparing how this template is configured with other "working" templates for a couple of days and everything looks Kosher, but surely I'm missing something obvious.

EDIT: The item(s) in question are imported by a data provider, and I've confirmed that for some reason Sitecore is not setting the "Workflow" and "State" system standard fields with a default value. That appears to be at least part of the issue.

EDIT 2: Followed the steps in this thread http://sdn.sitecore.net/Forum/ShowPost.aspx?PostID=45991 to use Sitecore Rocks to update all of the items to the correct Workflow State, but the update did not stick. For some reason workflow changes are not persisted for imported items.

EDIT 3: Clicking the Edit dropdown button under the Home tab displays the message "The item is currently not part of a workflow."

Answer 1

Standard values set correctly? Only have one Standard Values item for this template?

Generally, almost every time I run into a situation where X works on certain items, but not on others... it's a permissions issue. You've tested this as an Administrator I hope?

Sorry my suggestions are so vague, but it's hard to be specific here. We need some more information from you... When you click on Edit what exactly are you expecting to happen? I'm not entirely sure what you mean by "Edit mode" here. In Content Editor, all items are essentially in edit mode all the time... In my configuration, when I click on Edit, I am just locking the item. It does not change workflow state or create a new version.

These items are coming from a data provider... is your data provider handling Lock/Unlock calls properly? I know it's possible to use a data provider without implementing the entire Item API.