What I was seeing in the plastic caps is they are not very round. The best ones were the original gray ones. Also the black replacement caps were a bit bigger.
So being cheap, I might have dodged the bullet? I re-used my old caps and that was 3 years ago with no problems at all. I am finding that out more and more, new is not always better. Sometimes replacing things as preventative measures gives you more problems than you started with.