I have a Garmin 1495 T which has served me well for a long time but its now proving unreliable and often will not find satellites. I am happy to upgrade to a new model BUT I have a potential problem. I have the USA maps on an SD card. Garmin tell me that because this was a download the SD card will NOT work in a new model. Is this correct as I really don't want the double expense of a new Garmin PLUS a new map sd card!! Thanks Mike S