DS Loss of saved game data?

[TheMasterSpark]

Hello,

I noticed something strange last night after taking a break from playing DS. When I came back to play some more I noticed that much of my saved game data had seemingly disappeared, leaving me with 11 cleared cards and unable to go beyond stage 3. When I took the break I were up to 73 cleared cards and (obviously) had all the stages unlocked. What might have happened that could trigger a revert like this? The only thing that was different between the two occasions was that I had moved my laptop from one point in the room to another..

Has this happened to anyone else?

Edit: I'll add that my progress through the game had been gradually built up over this past week, I didn't clear all those 73 cards in a single sitting.

[Grand Octopus]

Never happened to me, though you've convinced me to back up my score.dat. Since that .dat file is the only thing that dictates your progress/unlocks (bestshot folder aside), the only plausible explanations are that one of your previous score.dats somehow overwrote your most up to date one / there was some sort of reversion within your roaming appdata where score.dat's located. No real idea how it could've happened.

[TheMasterSpark]

That's indeed the lesson to learn from this, though I guess there's not much I can do about it now. Good thing I never managed to capture any of the really hard ones before this struck at least.