Both shift keys sometimes decide to not work?

[onlinebacon]

Hi,

I just bought an ideapad s10e, and sometimes when I'm using it both of the shift keys decide to not work, and if you press them too much when this happens the backlight turns off?

Is this a common problem? Or am I missing something? It happened on the install of XP it had, and now the Windows 7 install I did today.

Cheers