Each message that comes to your pager is indicated by a triangle shaped icon along the top of your pager display. If the triangle is flashing, it means the message has not been read. Flashing icons will not delete off the pager when using “Delete All”.
To alleviate this issue:
- Press the Read button to bring a message up full on your display.
- Then use your left or right arrow key to scroll through all your messages until you have “read” all of them.
- Press the read button again which will bring you back to your date and time screen.
- You should now see the icons are all solid.
- You may now delete all your messages.
See the full pager manual here.