DS clicking on sleep mode?!

Whenever I put the Nintendo DS (original bulky gray) in sleep mode, it keeps making this clicking sound. It sounds like the noise it normally makes when it's put in sleep mode, but it keeps repeating. That shouldn't happen! It worries me because it sounds like this clicking noise this cheap radio I had made when the batteries started to leak.

A google search turns up a couple of other people with DS Lites having this problem (but no answers as to why it happens or how to fix it), so it's not exclusive to the original DS model.


WHY DOES IT DO THIS


EDIT:

I er, finetuned my search and found the root of the problem. All fixed!

What was the problem and how was it fixed?

Obsolete acekard firmware! Just had to update. I was worried that the DS has just gotten to it's age limit D:

Oh I see, well I'm glad you fixed it.