I also have this problem, while walking with the sansa clip+ in my pocket, at times it will lock up and freeze, appear paused, and I have to turn it off and on for it to work again, it seems to play on because the time on the track has advanced some, but no music is played until that normal restart. I also got mine from amazon.
Today, it cut out completely, a normal off and on didnt help, it just was blank black screen, and it didnt seem to respond well to charging up either, plus my pc didn’t recognise it. However doing a full reset like proposed here did seem to work, albiet it remained a bit sluggish, so it is working again, it’s just a question now as to whether it will stay that way or not.
I also tried a firmware update, but it said update service not available, but from looking at the updater and the number in the firmware thread, it seems like I may be up to date anyway.
Either way I’m not a very satisified customer so far, I’ve had constant “crashes” like the first, now a scare having be believe it was broken fully, and also the clip broke off of the back so I’ve had to go without one.
I do love the design, I do love the practicality and function of it all, but the reliability and the build quality doesn’t seem up to scratch yet.