Nokia N86 flash light problem

Hi. I have once strange problem with my Nokia N86. When I take a picture in dark place, where flash light is needed, flash power on once, picture is taken, but it is dark. Next time when I take next picture in the same place, flash doesn't work. And for third, forth picture, etc...... too. In camera settings, flash light is switched on "automatic". I change couple of times the main software of the telephone, not effect. If anyone have any suggestion.....
Thanks in advance.