davidfor, I have the exact same experience as you, except Windows keeps bothering me. These days I don't bother with checking for errors and I don't always bother to use Eject, but I did try most thoroughly back when I still cared.
It happens on most of my flash storage devices, and it does not matter which computer I use. Accoring to your logic, all my flashdrives, and my Kindle, have failing memory? Of course, I checked with linux tools and that doesn't seem to be the case...
I believe the common factor is the OS from Redmond.
