No it doesn't. I can take photos as normal.
Two possibilities come to mind:
1) CHDK is actually loaded, but the splash screen isn't displayed. Have you tried pressing the alt button (should default to "play" on this camera)
2) Your camera does not correctly detect the lock switch. We have seen this happen before on other cameras, and it tends to go unnoticed because most people don't lock their cards. Sometimes poking the lock switch in the SD card slot can remedy this. Or maybe the plastic tab on the card is out of spec and a different one will work. You can also try a locked card that does not have any CHDK stuff on it. The camera should report "card locked".