As a followup. Spent most of Friday on the phone with Humminbird and Navonics. Seems that the 788 doesn't recognize the community resource portion of the new Navonics update. But even after deleteing the CR file I've still got problems with the chip. Could have been corrupted during the several interrupted downloads I tried due to my slow dial-up internet. So anyway, Navonics will accept the chip back under warranty and ship me a new one. Lucky me, I found the receipt deep in the corner of the garage. Would be nice for Humminbird to tweak their software to allow the use of community resource material. Just saying.