When you are getting sealed while using a skill makro you will be disconnected from the server. In my case I used Dark Sight + Assasinate + Boomerang Step at Zakum.
According to Nuclear Cow, this bug is specific to Shadower Skills: Could anyone else confirm that this is the case?
I don't d/c when I use my buff macro (Meso Guard > Haste > Dagger Booster), nor do I d/c when I use my Dark Sight macro, or my Bstep > Savage Blow macro. Only thing that does d/c me is my macro for Assassinate (Dark Sight > Assassinate), but that's because Assassinate is bugged and d/c's you at Zakum. It's because of the fact that he has Assassinate in his macro, which causes d/c's. So yes, it's Shadower-specific, even Skill-specific for Assassinate.