What steps will reproduce the problem?

1. Install vanishnopacket v3.15 disguisecraft v4.3 and protocollib v2.2.0 on the lastest recommended version of bukkit (1.4.7-R1.0)
2. Become vanished, disguise yourself and you appear nonvanished as the disguised mob/player. If you then unvanish you will be seen as both yourself and the mob/player on the same position. If you on the other hand go vanish without any disguise, turn into a disguise, and then undisguise yourself while vanished, you become vissible.
3. Other player sees you and your stalking is over.

What is the expected output? What do you see instead?
Well, ive kinda already said this. Expected output when:

• being vanished and turning into a disguise: both the disguise and the player is vanished to normal players. - Instead they see the disguise.
• being vanished and undisguising yourself: still vanished and not vissible to normal players - Turns vissible to normal players.
• being vanished and disguised, then unvanishing: The disguise will be displayed and the player not vissible. - Both player and disguise are vissible inside eachother.

Do you have an error log of what happened?
No.

I think this is about it, sorry for a long ticket, and I hope you can fix this. :)

I'm getting this exact same issue with iDisguise. A lot of the time I'm unsure whether or not I am actually even hidden.