Lost Super Metroid save (Wii VC)?

[buddha]

So I've been playing Super Metroid on the VC for a week on and off. A fair few hours in, all fine. Saving at save points, occasionally exiting via the home button and picking things up from the automatic 'save state' or save slot. No problems

Just fired it up again and I'm looking at NO DATA! Eh? Quick look in Data Management from the Wii menu shows I have a Super Metroid save..

..also just noticed that my calender appears to have no record of any Wii usage this month!

Hmm.. this doesn't seem right.. Anyone got any ideas what's going on?

Thanks