The Argonian check in 1.3 doesn't work, it's not specific enough - the one in the group of scripts I sent you will fix it though.
The conflict is 100% with Streamline. Upgrading DH to 1.3 made no difference. Activating Streamline after already being in the affected area makes no difference, shortly after you get the Streamline activation message, the game crashes. So until this can get properly narrowed down, the DH readme needs to advise people to deactivate Streamline prior to entering Level 11. Should be perfectly safe to reactivate it after completing level 11.