Convection Oven Low Temperature

We are on our second convection oven from Dometic and this one has done the same as the first one. Set the preheat temperature to whatever, say 450, and the temp alarm goes off at 350. Reset it and it may come up to 400. Is anyone else having this problem or did we just luck out and get two that wouldn't come up to temperature? It's hard to bake (and my bride likes to bake) when the oven won't come up to temperature. Just curious.
John

Gail checked ours actual temperature (after several screwed up recipes) against the setting and it was either 50 or 75 degrees lower than the setting. This is our 2nd also, first one quit after 2 weeks.

Thanks Clark;
As soon as we get settled in Texas, I'll call Dometic and see if they have a solution. We can adjust the temperature as long as the desired setting isn't above 400 but if you want 450, you're out of luck. I hope they have an updated model that will work.
John

My 1st was made in Dec 05, 2nd in Mar 06. I discussed the unit quitting altogether with Dometic, but didn't know about the temperature problem at the time. Gail bakes little with it since she is the only one living in it for the most part, and it has been hot in FL since she moved in. If we were FT also, it would definitely be a problem. I'll be at Heartland next week, and I'll see what they say.