HI,
Not sure if this is considered a problem. Holding my cousin's D90 and he's complaining about the memory card green indicator light blinking non-stop. Read the manual for him (he is not into DSLR so I did the checks) and found nothing wrong with it.
Replaced the memory card and followed the formating procedures using both short-cut as well as via the menu and it is still the same. If he leaves it overight, end up the battery got drained the next day.
I really suspected is something wrong with the camera body...anyone with this experience? Not much about this problem in the web from my search too. He's overseas now and warranty card is kept somewhere that his wife cannot help locate. Got to either wait to send to NSC by himself or some kind souls got a solution.