Turned camera on but it won't respond in anyway...

I've used my camera about two weeks now and every now and then when I turn it on to take a photo, I press the shutter and it doesn't do anything. I receive two separate errors...depending on the cameras mood. It either says..."Err" which in the manual says "camera malfunction in which the solution suggests release shutter. That doesn't work and it doesn't turn off either...at the same time the "memory access card lamp" light is on. OR, I will turn it on and it will say "CHA" in which the manual says "error accessing memory card. It IS an approved card, I've tried TWO new ones now...both approved and the memory card is NOT locked on write protected. Resetting camera does nothing. Again, it won't turn off when this happens so I release the battery. That is the only way to kick it.