Nvu apparently has your image location set differently than where they -actually- are. The source is showing it expects them to be in the "Guerilla Marketing" subfolder, but they're actually in the same directory as index.html, and they also don't have the same filename you're asking for: in particular, the one I checked wants gj_banner_v4_250_250center.jpg, but on the server it's actually gj_banner_v4_250_250.jpg.
Somewhere in Nvu you need to update those urls to match the ones that are actually in use on the account, or you need to rename the images and put them in the subfolder Guerilla Marketing where the pages source is expecting them.