Pokemon White Saved Game Cannot Be Loaded ! Help!!?

I was playing pokemon White version on my Nintendo Dsi , i shut it down because i had to go , when i came back i started the game , and it says " saved game cannot be loaded , please turn off game and reinsert game card " , i did that like 15 times and it still doesn't want to load . Does anyone know how to fix that ? Please Help. And thank you .