I have been happily using MY Garmin for about 2 yrs. now and in the past week it has suddenly been displaying "Memory Full" and the on-screen response of [OK] used to make that go away - but - I stopped being able to have it set up a route. Now I can't even over-ride that error message. I can press [OK] endlessly it seems, without being able to go past that. Hitting the reset button doesn't help, nor does turning it off. Help?