I have a gas log (NG) fireplace. I do not use it much but fired it up for the first time this season. At first it would only fire up for a few seconds and then go out. After doing this repeatedly it finally stayed on for a few minutes and went out again. Fired back up for a while yet again only to go back out. The flue damper looks like it is working just fine and opens up once heated.
Not a windy day here either and no obstructions to the intake around the bottom or sides.