Hello all, I hope I'm posting this in the right spot, so here goes. I have a canon 50d and have been using it for time lapse using the canon TC-80N3. I have a 16gb card and am using the S3.7m quality setting. The exposure is 15sec and on the timer, the self timer is 4hrs with the interval at 25 sec. The Exp count is set at 00 The problem is that the camera stops shooting after about 400 shots even when the card is far from full, in the top right corner of the LCD screen the  flashes and nothing can be done unless I pull out the battery and replace it, then I can start again. Though by this time what I wanted to capture is long since gone. All this while the timer continues as if nothing has happened. Is there a setting that I can change on the camera or the timer? Am I doing something incorrectly? Any help will be appreciated, many thanks, Mick.