Multiple notices cannot be filed in the same second
file_notice() keys its entries by the Unix time() stamp that is only to the second. If the system wants to notify the user about something important (that flashes on the webGUI notices) and there are 2 or more problems in the same second then only the last call to file_notice() is displayed on the webGUI.
Updated by Phillip Davis about 6 years ago
This is one possible quick-and-dirty pragmatic way to fix this. Increment each file_notice() to the next second. If you get 10 of them in 1 second then they will be reported all as if they were a second apart over 10 seconds.