Hi Jamie, this definitely sounds like a glitch in Data Grab. You can have duplicate titles no problem. You should NOT have duplicate url_titles in the same channel, but frankly there’s no reason they couldn’t be added via something like DataGrab and still work in the backend. On the frontend, if you are using category titles- you’ll have a problem, because it won’t know which url_title you’re referring to. You’d need to go through and make sure those are unique.
What really really can’t be duplicated is the entry_id- that much be unique and mysql should reject a duplicate.
But if it’s an issue of duplicate url_titles? You should still see all of the entries in the control panel. It’s only on the frontend things might get confused. And if the duplicate url_titles are in different channels? There shouldn’t be a problem.
Personally- I would roll back to a db from before the import, as I’m not sure I’d trust the integrity of the data at this point.