WOW - Vanishing Bug : World of Warcraft General Discussions

Vaneras from Blizzard commented over the Vanish bug...

Actually Vanish is working as intended. What many see as the Vanish bug is in fact a latency issue between your computer(client), the realm(server) and the computers(clients) of other players.

Here is an example of what can sometimes happen, which leads to the perception of Vanish being bugged: If an enemy rogue attacks you using Eviscerate, a command is sent to the realm telling it that Eviscerate is being used by that enemy Rogue. If you then use Vanish right after the enemy rogue uses Eviscerate, the realm is in the process of acknowledging his Eviscerate command while your Vanish command is still being sent to the realm. The acknowledgement of the enemy rogue's Eviscerate command is then being sent to your computer, and at the same time the realm is registering that you used the Vanish command. The result of this is that your client can take you out of stealth because you were hit by damage, even though you used vanish, because there is latency somewhere between you, the realm and the enemy player.

Such latency issues cannot be corrected with a simple patch or hotfix due to the very nature of how data is being sent and received with the current Internet infrastructure, however the developers are aware of this issue and they will come up with a proper solution if/when one is found, or if one presents itself.

Thanks