Thanks but it is still not working even when I do that.
Its very odd I've got 8 separate trackers that all work in my 1.9.11 instance and I can import/export from them fine. In my 2.0 version of the same data I've now checked and 7 of them are fine on import and export ie I can export all their data and then reimport the same file after cutting it down just for test purposes and deleting the itemID values. But with the 8th Tracker I just keep getting this error no matter what I do. I'm going to rebuild the dataset from scratch in the 2.0 instance and see if that makes any difference.
If anyone else has any ideas I'd really appreciate it