Wow! Venus was incredible. Just based on having seen this thread, they contacted me, and offered to send me a whole set of grommets (as the rings are apparently called) at no charge! All the way to Israel! It seems grommets used to be simply brass, but they now make them gold-coated, and my humid climate could be causing problems.
I just feel a need to write this, in case someone gets a bad impression of Venus from the first post. I would never have dreamed that they would search me out to help.