Made Popular: Jul 20, 2008 - U.S. and Iranian envoys had their highest-level diplomatic contact in 29 years Saturday, but the seven-nation gathering in Geneva on Iran's nuclear program quickly was brought to a halt by Iran's refusal to say whether it will suspend uranium enrichment. In a break with long-standing policy, U.S. Undersecretary of State William Burns joined Iranian nuclear negotiator Saeed Jalili, European Union…