Couldn't mine/skin heroic bosses (wotlk)

[Ughmahedhurtz]

They apparently changed this unintentionally as part of raising the cap on skinning to 525.

[ILikeTwins]

I think this changed as part of 4.0.1. Something to do with the underlying updates to max level mining/skinning and heroic bosses being skull level still.

I think if you have the gatherer enchant (+5 skill to mining/skinning/herbalism) on a set of gloves then you can still skin/mine them if you have max skill since that will get you to 455 which I believe is what you need in order to skin/mine those bosses.