[herber@wirehub.nl]

I have encountered what might be a bug, I don't exactly know.

Sometimes, it seems that an empty entry is created in the table xcart_order_tracking_numbers.
The orderid will be filled in, but no tracking number is present. I haven't been able to find out when these records are created exactly.
In all these cases, this record is created before any tracking number is added to the order by hand. In this case, the order wasn't even shipped, it was picked up, I made up the tracking number that I added. The empty record was already present.

It is not possible to add a tracking number in the order, it will give the error 'Empty ids'.
It can also not be deleted in the order: it will look like it is deleted, but return upon reloading the page.