Its a Bug looks Like..
Saw reports with this kind of Stuff happening with battles next to Doors Since 2.0
(now i always avoid battle next to then.. kind anoying becouse i have to Make then Come to Me Most of times until im able to start atack.)
Will give yu a Spoiler to Skip this Part and go direct to the Boss..
YU can use Fly on the Outiside to go to the Necro,Ketric roon.. and just go up.. But Jaheira maybe Die if yu dont fight with her and let her fight alone.. but if yu go in the Dark side she is already dead and its the easy way to skip the entire floor of moorise tower..
i Hope this Tip/Spoiler can Help yu in Some way man..