phpstorm7.1, drag file from project(left) to server(right), the project file delete, i think it's moved. phpstorm7.0 do not have this problem. It's a new behavior, or just a bug?
Dragging moves remote item - see http://www.jetbrains.com/webstorm/webhelp/accessing-files-on-web-servers.html, 'Moving a file or folder '; try dragging with Ctrl to copy