Canon PIXMA MP150 User Manual page 52

Important
Note
50
Reading From And Writing To A Memory Card (MP170)
Windows 2000, when the write protection is enabled on the machine: If
the computer does not detect that the write protection is enabled, a
delayed write error might occur and data could be corrupted when
attempting to copy data to a memory card.
You cannot write to memory cards when the machine is in Memory
Card mode.
To change the write protect setting while a card is inserted in the Card
Slot, unplug the USB cable before changing the setting, then plug it back
in afterwards. The new setting is not applied unless you plug the USB
cable back in.
Chapter 4