First thing that comes into my mind is: wrong server configuration, maybe PHP does not have the write permission to image files?
"/data/uploads/imanager" and "data/imanager" should be writable for PHP
Or maybe PHP GD extension isn't installed? http://stackoverflow.com/questions/22831...without-gd
"/data/uploads/imanager" and "data/imanager" should be writable for PHP
Or maybe PHP GD extension isn't installed? http://stackoverflow.com/questions/22831...without-gd