Scanning B&W Negatives - No ICE!

Apparently when scanning in black and white negatives (true black and white, not C-41 black and white), you can't use Digital ICE or any other technology that relies on infrared scanning to pick up dust/dirt on the negative. I'm not sure why, but when I scanned in a few B&W negatives with Digital ICE turned on, everything looked terribly posterized. I saw a few posts online about Digital ICE "not working" with B&W negatives, so I tried turning it off and everything was fixed. I'm guessing that the infrared scan incorrectly interpretes some of the emulsion itself to be dust or dirt, and removes it, leaving huge holes in the grayscale of the picture that then results in posterization.