Just received this email from amazon uk:
Since you ordered this product, the manufacturer has confirmed that they have discovered technical issues with Star Trek: The Next Generation - Season 1 on Blu-ray. There is an anomaly in the English 7.1 DTS Master Audio track, resulting in an undesired playback experience when listening to some episodes in a 7.1 or 5.1 Surround Sound environment. In addition, the manufacturer is taking this opportunity to correct a few minor issues that were found on other episodes.
A corrected version of this product will soon be available and we are working to ensure that you receive a replacement copy of Star Trek: The Next Generation - Season 1 on Blu-ray as soon as possible.
Your complimentary replacement will be dispatched to the same delivery address as that used for your original order.
No action is needed from you and there will be no charge for this replacement.
The replacement will be sent out as soon as new stock of this item is received from our supplier. We'll send you an e-mail to confirm when your replacement has been sent, and you will be able to view the status of this order via Your Account at the top of any page on our website or use the following link:
Thank you for your patience and we hope to see you again soon.
Customer Service Department
So no word of a date yet but at least I haven't had to contact them to sort it out.