Oh, one last thing: that could also be the result of improperly-set Color Space settings; perhaps your film has more gradients than the colorspace you're trying to use. You could be double-profiling (if you use Windoze, it is very easy for this to happen), where you tell the software one colorspace to use, and you've told the operating system to assign another by default (right-click on your scanner, select properties, and then a window with a "Settings" or "Color Space" should be there; remove anything set in there, if it is)
Sometimes, if you've reinstalled certain software, or even used a different USB port, Windoze will pretend to know better and undo your previous settings and set what it, in its Infinite Wisdom, thinks is the only good thing for you. You know, like those guys who go into certain brand threads and bash away predictably 😀