I'm finding its only 50% of the time emptying the Sandbox properly. Also I'm finding a lot of the time when Maxthon 3 opens for me my add-ons are missing..So I run unsandboxed, then close then overwrite and open again and its hit and miss if they are there.
Anybody else having the same problems...I'm having it with 2 x PC's so its not a particular machine.