Yes, what Darkhorse said. If you use the ICE on standard 'silver' black and white film, it creates those fuzzy spots. You can use ICE with XP2, or BW400CN, though.
Incidentally, I find I get better results with Silverfast than with the Epson software. It's not as good as the Epson software for batch scanning a load of 35mm, but in terms of the quality from individual frames, it's much better.