Today I bought the Canon 50D at a local photography store. I did some test shots with it, about 110. After I connect the camera with the USB cable and transfer my photos to the computer and unconnect the camera from the USB port I get Err 80 on my top display and the camera is frozen. The only way to fix this is by taking out the battery (turning it off with the switch does nothing). After I take out the battery it back on track and I can shoot like normal. The error 80 is an image or electric control malfunction has been detected. Should I take it back to the store for a refund/exchange ?