On the official WOW Forums a sticky post warn us that: We have implemented a hotfix to all realms during today's maintenance which we had originally scheduled to release with patch 1.12 that changes the functionality of temporary item buffs (e.g. poisons, sharpening stones and shaman weapon buffs.) While we only just recently allowed the affects of these temporary item buffs to persist upon zoning and logging out, due to the extra demand it was placing on our hardware we've decided that for the time being, it was best to revert the change. We do anticipate this functionality will be available again once the anticipated hardware upgrades have been completed in preparation for the Burning Crusade's release.