Iran has always been a good friend of India, in spite of the tense relations Between Pakistan and India. Iran has never morally supported Pakistan on Kashmir and always tends to lean over Indian side. In February-March 1994 Iran forced Pakistan to withdraw a resolution on human rights condition in Kashmir at the United Nations Human Rights Commission (UNHRC) session in Geneva. Iran and Pakistan have lost unanimity of views on Kashmir and other issues including Afghanistan since then. So the news of 2 Indians selling weapons to Iran is no surprise to me.
Your really misonformed about history and current affairs. Iran publicly supports Pakistan's Kashmir stance. Though recently its a bit mellowed down. Inititally, and uptil around early 90's they used to openly say Kashmiri should be given the right to choose. Now they say the issue must be resolved with participation of all three parties concerned. Never have they publicly stated any opposition to Pakistan's stance.
In both the 65 and 71 wars Iran openly sided with Pakistan. In one or both wars , not sure, Iran provided free fuel to Pakistan during the war. Also (a bit of trivia) Iran was the first country to recognize Pakistan. The relations soured after Pakistan's support for Taliban inspite of the laters massacres of shias of Hazara tribe in Afghanistan and also sectarian violence in Pakistan. Anyway, just thought i'd give a more accurate picture.