0% save freeze bug, annoying but not game breaking

[Ripperzipper]

I have noticed that on all of my characters I spend alot of time playing I eventually run into this bug. I will leave a dungeon and it will begin to save and stick at 0%, eventually I am forced to end the t-engine task and return to a previous save however the save will get very slightly corrupted and all of my map progress will get wiped and only the area I come out to on the world map will be revealed. I also noticed this removed my warp portal to the sher'tul (spelling?) fortress so I must now find myself a new waterbreathing item and get in there again.. I also noticed that the thunderclouds over Derth arent there anymore however the elementals are inside still. I am unsure why this bug happens and have only run into these problems with it but my save is otherwise fine... if there is any way I can help find what is causing this bug please feel free to drop me a PM with the info and/or a program I can use to isolate this and I will be happy to try and recreate it.

EDIT: Returning to sher'tul manually and leaving via the quick exit has not brought back the quick port :S