First off, very cool app. Love what I have got so far. I work for a local high school and am playing around with this to look for weak spots in our coverage. This is a school for 2000 kids so its very large. After scanning about half of one floor I have started to have issues with the program freezing up and then the map I was using no longer working. I will send in some of our maps that we have been working on, one good and one bad to see if you can see anything with them. Thanks.