Not as much as they despise the West, apparently.
I call . I don't believe it, there's no way that the Iranian government would deal with the same Taliban that murdered the Iranian diplomats at Mazar ê-Sharif less than a decade earlier. Perhaps that the Iranian government funded some Shi'ite splinter group, but it doesn't make any sense for them to fund the Taliban as a whole. There's one sentence I find troubling in particular:

Ideological differences between Iran, a Shia Muslim state, and the Taliban, a Sunni militia, are thought to have been settled in light of the shared aim in attacking coalition forces.
The Taliban aren't just "Sunni militias", they are hardcore Sunnite fundamentalists to the extreme. It would not make any sense for them to forge even a temporary alliance with the Iranians, as the Shi'ites are worse than non-believers, they are apostates. Or something. I find it hard to believe.

A different explanation might be that there is a lot of corruption within Iran itself. It might be that the government either didn't know or didn't care about weapons smuggle to Afghanistan.