You are exactly correct. The IR dust and scratch cleaning facility WILL NOT WORK with conventional B&W film or Kodachrome. It will make a huge mess of things. It works fine with E-6 and C-41 process films (including BW400CN and XP2), although I had better success in that regard with Digital ICE on Epson Scan that I do with VueScan. I mostly do my dust spotting and scratch removal manually through Photoshop, so it's not a big deal for me.Sam, just note that the image-cleaning facilities on the Plusteks are to do with the software, not just the scanner hardware; SF8 and Vuescan will both attempt it if you ask them, and as I understand things, are intended for colour films (and perhaps chromagenic (C41) B&W like BW400CN and XP2S) because they use an IR channel supplied by the scanner. Silver halide b&w film doesn't respond to the IR channel in the same way (or at all).
If I'm wrong about the technicals of this I hope one of our scientist/engineer types will come along and correct me ...