Several of these type codes usually appear after the battery has been disconnected. Try clearing the codes that appear and then check to see if they reappear. I had several of this type just after I replaced my battery. Also, I believe that I have read that codes in "history" are not nearly as important as those appearing as "current."
Yes, loss of keep alive memory is caused by the battery either dieing or being unplugged. As for the History and Current deal, I just plain ignore it. There are a LOT of systems that can't be checked while the car is not moving, so of course those problems will be marked as history (RSS problems for example). They are still problems none the less. If it is marked as history, it is a problem that has occured in one of the last 50 start ups. If it is current it is a problem that has been discovered, or rediscovered on this current start up.
Although it is true that there are many unthreatening codes, like the one you're experiencing, and some of the modules do have computer farts and spit out unnecessary codes. My point is that the meaning of the code determines its importance rather than current or history status.