Hello, i've noticed that the bottom few rails on my chrome towel rail, on their undersides, have signs of corrosion. The tops of the rails look fine, as do the higher rails. It's 3 years old - is this normal? Is it ok to leave, or is this bound to get worst? Why's this happened - could it be due to high levels of condensation in the bathroom (there's always wet towels on there) , or corrosion from inside out? Thanks for any info, Matt