We're running Mingle 3.1 and I'm having trouble importing records into Mingle. I'm really just trying to do a bulk update, changing the card type and re-mapping a few other properties (for example, changing 'Criticality' to 'Priority'). I tried importing ~650 records from Excel, but only about 300 went through (they don't even appear in the preview and going Back and then previewing again has no effect). Sometimes, I can break the records into smaller batches and they'll all go through. Many times, however, Mingle will only preview/import the last row. I don't think it's data-specific, because when I copy the n-1st rows from Excel, I still only get one row (the n-1st now).
Have others seen this behavior? Is there a better way to do this kind of bulk update?