Olympus C-5000 Zoom green led blinks

Hi,
subj. Normally it should blink when having trouble focusing, but this is different. From time to time, when I power on the camera, lens extend, and after some seconds they go back in, and camera acts as if it was powered down. So, I switch it off, green led blinks for about 5 seconds and then it's really switched off. Then, I power it on again, and everything works as expected.
Such funny things happen mostly when the camera is not used for some period, - couple of hours or a day.
I read somewhere, that green led blinking indicates potential problems with memory card.
Anybody experienced such things? What could be the cause and what should I do? (the camera is quite new, used for about 1 - 2 months, at the beginning there were no such problems. warranty period, of course, still in effect)