OK, just go the 478 unit that was swapped out for a 378. The reason I got rid of the 378 is that you could not load route data from a PC on it due to the combined Inland lakes and CN NT mapset that it uses. The 478 on the other hand has the normal version of CN NT so all is good. I had no problems loading up my routes to the unit! Can't say enough about the customer service from both TVNav and Garmin. Oh yeah, I see on the Garmin web site there's now an asterix on the 378 page that mentions that it uses a unique map set.