I'm not sure if this is a bug or not, or if it even existed in .62 but inferno does not apply a burn effect currently.
Does not apply in v62. The skill window at level 30 says: MP -30, Damage 150% Where as bbb.hidden-street.net says: MP -30; Attack power 160% with fire attribute, burns enemies for 6 seconds So it was before big bang but not v62.