I have been in contact with Brunton and they are investigating.

First, I have been advised of another recent batch of 40LUs that had similar issues.

Second, Brunton claims these are all from a single shipment from Sweden and that with the exception of these bulk orders, none have been circulated to retailers. They say they have instituted a 100% check of any further shipments until such time as they solve the problem. Silva is looking into the issue, but have not yet reported back.

I will update this as further information is available.