Russian attitudes towards homosexual relations are certainly different than parts of Western Europe and the United States.

First, I don't think it would be correct to characterize Russian attitudes as tolerant, though perhaps more tolerant than other places. The Church was, unsurprisingly, opposed to homosexual acts like sodomy and required a long period of penance, though priests would be excommunicated. It seems that the Church's attitude was one of practicality - they knew it would happen, condemned it, but not too strongly (no death penalty).

It was not considered desirable to engage in homosexual acts, but it wasn't completely disgraceful. However, the tide began to turn when Peter the Great instituted corporal punishment within the military for soldiers caught engaging in sodomy. Then, Nicolas I instituted a statute that made homosexual acts punishable by exile to Siberia. But the status quo didn't really change; homosexual sex and relationships were often time an open secret.

It is certainly false that the strong condemnation came in the post-war era. Pre-war Soviet law made sodomy punishable by several years in prison. I think it's more correct to say homosexuality has always been looked down upon, though not to the extent of places like England or the United States, and Russia has a very different relationship with it.

Untrue. Homosexuality was legalised in the early days of the revolution under Lenin, but was outlawed once more in the conservative turn under Stalin in the 30s. It didn't have anything to do with WW2. Source: Everyday Stalinism by Sheila Fitzpatrick.

Incidentally, the wikipedia article on LGBT rights in Russia is pretty good: http://en.wikipedia.org/wiki/LGBT_history_in_Russia