If it’s the heat I suspect you do have a defective unit.
While heat can always be an issue with electronics, room heat should *never* be a problem unless you’re just a desert rat. The operating temp of the Live runs up to 95 degrees room temperature, and if you’re keeping your house warmer than that I’m not sure what the point of having a house is (might as well just be outside :>).
Obviously you don’t want to block the vents or have it near any source of heat (like a disc drive, or sitting on top of a receiver) but it doesn’t sound like that’s the case here. If it’s still under warranty I’d get a new one.
