In Skyrim, I make backups of my quicksaves very often, and I have a question: what will happen if you save the game more than 999 times (with overwriting, while I made 150 saves in Skyrim, I have only about 30 individual save files)?
Skyrim has a major bug in it (this same behavior is found in Oblivion as well) where after you reach 1000+ saved games, it very frequently stops saving games on user demand, but auto save continues to work. I have experienced this bug on the Xbox 360.
This issue has been reported by another player over at http://www.gamefaqs.com/boards/615803-/61870496 and I would have loved to add my notes there but the idiots oddly archived the thread so that no one can comment on the problem.
The real pain here is that the issue seems to have a spillover effect that also causes problems for other Skyrim accounts on the same Xbox even though they have far fewer than 1000 saved games. For example, my daughter has 200 saved games and started having problems saving her games after I hit the 1000+ mark.
In Oblivion, the manual game saves would actually work but they would appear at the bottom, or near the bottom, of your saved game list and you could go find them with effort. But this same behavior does not appear to be happening with Skyrim. It is simply not saving the games when you tell it too. The interface will give the appearance of the game being saved, but it will not be saved. Only auto saves work and we're now having to go through backflips to trigger auto saves when we want to save the game.
In Oblivion I was able to make things behave better by going through the horrible Xbox interface and spend hours deleting single game saves, file, by, file, over, and, over, for, hours, because there is no bulk delete functionality on the Xbox, but I have not yet tried this this pain in the ass solution with Skyrim.
Bottom line, because of Skyrim's poor game design where game saves are involved, you should develop a habit of capping your total game saves to well below 1000 by saving over previously saved games.
To my knowledge, there is no known fix for this profoundly bad flaw in the Skyrim game save architecture.
After I passed 1000 saves while playing Skyrim on Xbox 360 the system seemed to be saving but when I would quit the game and come back it would load a previous save. The later saves were not visible when trying to load. When I deleted several of the earlier saves I saw that the later saves started showing up and were available to load. Now when I save, the system acts normally. So it seems that after 999 saves the system does still save but it cannot show or load them until you reduce the number of saves. I hope this helps someone else.