I would definitely send it to them. All you're risking is a few bucks for postage. If it says "Lifetime Warranty" on a product, I believe in holding a company to that. If they don't mean it, they shouldn't say it!! I have sent several items back to manufacturers over the years, and usually I am satisfied with the results.
I think that many people are reluctant to do so, but I'm not bashful, in that respect. Also, I believe many manufacturers count on only a small percentage of failures actually being returned. Items that someone else has discarded/given up on, are still covered by the warranty. Some warranties restrict to original purchaser, while others make no such restrictions.
Anyway, I'm curious how it turns out for you.