Remember, although Pakistan is the supposed first muslim country to have a nuke, it has never fully detonated one, it only lit off the implosion charges.
Iran wants to be the first to do so and show all muslims that shiism is the most potent of muslim sects in order to cower Saudi Arabia, Iraq, etc. Especially Iraq where there is deep hatred since their war and Iraqi shiites refuse to follow Iran's political leads.
In a surprise change in policy Iran is now in favor of the Dollar:
Iran Selling 45 Billion Euros of Reserves for Dollars
http://www.businessweek.com/news/2010-06-02/iran-selling-45-billion-euros-of-reserves-for-dollars-update1-.html