I'm sorry about the issue. To confirm, you open a picture, then press the FUNC SET button, then select the lock icon, then what happens?
Would you like to delete all pictures?
Please reply at the box below. Thank you,
Hi the first thing to confirm is are you unlocking the photos on the internal memory or the card? If the card then remove th card and you should see a sliding unlock switch on the card itself.
Your camera manual is here:
Page 13 covers the memory card, you may have inadvertently locked the card which will stop you deleting images... Or taking any more to the card