Importing old waypoints on Humminbird sounders

Recently I replaced my Humminbird 998 with the newer 998HD. Before removing the old sounder I ran through the standard 'export all nav data' option to save all my GPS marks to an SD card. I then removed the SD card and deleted the waypoints form the unit. When I go the new 998HD I installed the SD card and turned the unit on. Expecting the waypoints to automatically load I was surprised (and a little concerned) when they didn't appear on the chart. I checked the SD card on the computer and correct .hwr file was located in MATRIX folder as it was supposed to be. And the timestamp on the file indicated it was created when I exported the data. I also knew the new unit was reading the card correctly as the snapshots were all present. In an effort to ensure I hadn't lost all my marks I installed the Humminbird PC software on the computer to open the file. This was a bit of a mission as I am a Mac user and so far Humminbird have not ported their software application across to OSX. The file loaded correctly and all my waypoints were definitely on the card. After reading around some forums I soon found the answer. 

To import waypoints from an SD card the unit MUST be powered on BEFORE the SD card with the waypoints is inserted. This is only a recent changed that occurred in a firmware update. Prior to this the card was examined for new waypoints every time the unit was turned on. But not any more. Once the unit is powered up, and the SD card is inserted, a dialogue box asks if you would like to import the new nav date. Once this is confirmed the waypoints are imported and everything is ready to go! Happily I can report that the link between the waypoints and the thumbnail images are maintained.