Um.. I don't know much about Canon.. but there are some general DSLR steps you can take..
Charge up the battery and leave it outside for a couple hours. Maybe even try a different battery altogether, batteries can often be the cause of odd problems.
Update the camera firmware to the latest one.
In the menu, there is probably a "reset to factory defaults" function - try this, it might fix settings you didn't know were in effect.
Other considerations: Is there a lot of static in the environment? Is there a universal remote being used nearby? Is the shutter button damaged/wobbly? Interval mode or timer disabled?
Also, make sure your kid is not playing tricks on you to get you to buy him a Pentax