Hi Norman, Yes I was gobsmacked when I read that article, I have been using IPA for years and never have a running problem although I do get a lot of black gunk building up. That said I run very heavy old Athearn and Bachmann US diesel locos (all DCC), they weigh a ton and have very good all-wheel pick-ups, they will still run on the dirtiest of rails. I am going to trial non-polar cleaners but it will take some months to get results - watch this space! Ian.