There's certainly no love lost on either side between the people of the two countries. They don't like each other. By contrast, Iranians like Americans and Americans like Iranians.
On the government side, the Russian government has not seen the Iranian nuclear program as an urgent issue, as argued repeatedly in the meetings of the P-5 plus one. The five permanent members of the Security Council plus Germany have been meeting regularly about this matter. Russia has repeatedly argued that the Iranians are further behind than other countries think, we have more time to deal with this, and at the end of the day the Iranians will come around, but we have to be patient and tolerant.
One gets the distinct impression that this issue is not high on the Russian agenda, and Russia sees no particular reason to be cooperative with Europe and the United States when they have been unhelpful, as far as Russia is concerned, on issues like Georgia. Indeed, the only way we ever got the first Security Council resolution about Iran through the Security Council was by agreeing to keep our mouths shut about some developments in Georgia at the time.