When we turn on our gas fireplace switch it will sometimes come on, but typically doesn't. When it does ignite, the flame wil only stay lit for several minutes and then goes out. The pilot light remains lit, so that is not the issue. Do you think it is an electrical issue or a problem with the insert?
From the sound of it some kind of safety has kicked in. There's probably a thermocouple that's connected to a cut off valve of some sort. If the gas is on, but the thermocouple is too cold, it cuts off the gas (this is intended to prevent something blowing out the flame from filling your home with gas!).
Look around and see if you can spot the thermocouple and make sure it's not bent out of the way or something silly like that. Beyond that, I'd call for service on the thing.