Last Thursday, my Sidekick LX developed a Trackball Issue. That is, the cursor wouldn't move up when I moved the trackball up. The usual fix for this was to press hard and hope the problem clears itself. That didn't work.
As it happens, I bought the LX last year, on my birthday. The warranty is for one year. My birthday is tomorrow. So, Sunday, once I'd worked all that out, I called T-Mobile and confirmed via their phone diagnostic that, yes, there was a trackball issue, yes, I really couldn't do anything about it, like, oh, popping the trackball out and cleaning under it, and yes, they'd do an advance and exchange.
So, the new phone has arrived, much like the old one, except personalized with some sports guy's name. And, it has a working trackball. Yay!