Yesterday I was out riding on my motorcycle with my Karma as I have done several times before. It played no problems for about 2 1/2 hours straight, turned it off for lunch, and after lunch it played fine for an hour until all of a sudden it just stopped playing mid-song. This was just before a scheduled stop, so I pulled the Karma out of my pocket and it showed as playing but wasn't. I tried the riostick to see if it did anything and after a while it did, but still wasn't playing, so I tried to just turn it off, but it sat there for quite a while with the hourglass spinning. After far longer than it normally takes to turn off I got worried and found something to push the reset button. I turned it back on and it started playing a few songs back from where it was at. It played fine for 45 minutes and then stopped playing but I couldn't easily pull over to check on it and it started playing again after about 2 minutes. The same thing happened 15 minutes later and 10 minutes after that I pulled over and the battery was at about 10% so I turned it off.
It is playing fine so far this morning but lately I have been getting momentary breaks of less than a second, kind of like a CD skip which I'm pretty sure aren't a problem with the MP3.

I have firmware 1.68 and a little over 18GB on the player.

I would say try re-flashing the firmware (just in case) and if that doesn't work to contact rio for an RMA....if, of course, you can contact them...

My first unit and it's first ride info is here. I replaced that first unit, and the second. (Second was DOA out of box, looks like Best Buy stockers may have abused it).

My third unit does exactly what yours does. It a few times stopped playing mid song, and would resume minutes later. After the 4th time, it locked hard, and I just put it away since I had nothing to reset it. From what I can tell, the hard drive has issues with the vibrational forces felt on a motorcycle, and will go into a state of non functioning for a few minutes, or sometimes until it is powered off. The vibrational sensitivity seems to be much worse then a normal 2.5 inch disk. I knew a rider with a Creative unit that had a 2.5 inch disk, and he never had an issue like this on it.

My poll on Riovolution seems to be mixed. For several, it works fine. But for 2 in the poll, they report complete lockups, but didn't bother posting about it.

Unfortunatly at this point I am looking into an iPod. I'm going to see if I can borrow my friends second generation unit and see if those hard drives have similar issues. For me, a portable player is rarley going to be used outside of my motorcycle rides, so I may have a new Karma with a 3 year warranty up for sale soon.

That sounds like a reasonable but unfortunate explanation as I too bought the Karma largely for riding, but I do listen at work as well. I suppose as long as there's no threat of permanent damage (??) the biggest problem when this happens is that apparently it eats the battery.

It's too bad, because I know other players have no problem on motorcycles. For example, my PJB-100 (with a 2.5" drive) spent the better part of a year strapped to the fairing on my bike with no padding or shock absorption, but absolutely no ill effects. If you're looking for a fairly rugged player cheap, you could get one of those for a good price since they haven't been made for a while.

I haven't taken the Karma out on the bike yet, mainly because I don't get on the bike as often since I haven't had time to fix it recently. However, even if the bike was in 100% working order, I'd be wary because of everything I've read, and would probably keep it in my jacket or something to absorb the vibrations.