Is the Integrity Problem just with Top Executives?

In today's WSJ, the CEO of Boeing continues to run into challenges implementing his ethics campaign with employees. Harry Stonecipher wants everyone to sign a code of conduct that states they will not "lie, cheat or steal" amongst other guidelines.

Mr. Stonecipher is clearly a Charismatic decision-maker that makes decisions quickly based on his gut. He grounded two helicopters on the spot when some executives in a division were using them too much. Although the Boeing stock price is climbing, criticisms about its ethics continue to be rampant.

Would you sign a "code of conduct"? Are the ethics problems in companies today confined to just those at the top? What needs to take place to correct them?