Lightbulbs and magazines

These have likely reached some of you via the Internet. But fun for those who may have missed them:

Q: How many freelancers does it take to screw in a light bulb?
A: No one's sure. The ones who can screw them in, we can't afford, and the ones we CAN afford can't screw in a light bulb.

Q: How many production editors does it take to screw in a light bulb?
A: Only one, but that's going to cost us an extra production day.

Q: How many copy editors does it take to screw in a light bulb?
A: I can't tell whether you mean "change a light bulb" or "have sex in a light bulb." Can we remove the ambiguity?

Q: How many managing editors does it take to screw in a light bulb?
A: You were supposed to have changed the light bulb last week.

Q: How many copy editors does it take to screw in a light bulb?
A: The last time this question was asked it involved managing editors. Is the difference intentional? Should one or the other instance be changed? It seems inconsistent.

Q: How many art directors does it take to screw in a light bulb?
A: Does it HAVE to be a light bulb?