I'm having baking issues...

[jennythereader]

I've been on a bit of a baking bender lately, but it's not going so smoothly. Everything seems to be taking longer than the recipe calls for. Some brownies that should have taken 20-25 minutes were still not quite done in the center when I took them out after 35 minutes. My current theory is that the temperature dial isn't accurate.

Can anyone out there loan me a oven thermometer so that I can test this theory?