Hi Les, the first thing, I've not experienced similar, as I don't use such racks, ideal there use maybe, I'd not chance reaching over the lathe for tools on such a rack, the other thing besides you're finding the tool drags on the rest, is with grinding/sharpening on a dry system, the metal being removed, I consider would stick to the tool, again adding resistance, if not transferring to other surfaces.
The option is to strike the tool every time to distroy the magnetism, yet over time could result in tool damage. IMHO.
Cheers David