I recently bought a brand new 10 MP camera (Canon Powershot s90). I definitely set the camera to shoot pics at the highest resolution, and still the images are shot at 2 MP. What gives? The only thing I can think of is that I am reusing the SD card from the old camera, and did not reformat it for the new one. There were still pics on there, so I didn’t want to erase them immediately. Is that the issue, or is it something else?

Note: I edited the Q to more accurately reflect the issue. Sorry for any unintended confusion.