Which version of Vue?? The Esprit lineup has terrain resolution import limitations that were removed for the Professional/Infinate lineup. It's not as much a question of size of file as resolution in that instance (2048 x 2048 I believe is the Esprit limit). Beyond that I'm not sure, I've never had any problems other than that (and the mars data has some strange things going on with it but that's a whole 'nother issue.