Possible reasons:
1) Google has turned this off
2) Rather than informing us, it is sent to a Adwords worker for review
3) Google has acknowledged my spelling skills by turning it off just for me :)
If they have turned it off, this could be an extra step to reduce their ad checking and save costs. It already seems to be quite clear that only some ads ever get checked by a human (whereas they used to check every single one).
Rob.