My son's DSi is having  problems.  I've only had it for about a month.  All of a sudden it wouldn't start up.  Charged it up for awhile.  I would turn it on, it would stay on for a few seconds then turn off.  Then a day or so later everything worked fine.  Today we were both using it for awhile, with the power cable plugged in, with no problem.  We went to play "Brain Age" and the date and time were off.  The DSi had reset to 00/00/2000.  This was the same as the last time we'd had a problem.  I reset the time and date several times but it stayed at 00/00/2000.  I turned it off and now when it comes on I just get 2 gray screens, no graphics or menues.  Any idieas?