Not really a new suggestion but along the lines of MAB's one, I used to crash pretty often in Port even with minimal graphics settings until I changed my MaxTextureMemory to 2047, though I've the specs for it. Now I just crash at what I assume is the usual expected levels given the people around me usually crashing roughly in the same time frame if they haven't relogged.
If this isn't an option, and you often arrive by Port by caravan, you can use the long wait time during the ride to log out and back in & refresh your NWN before the caravan reaches its destination. Takes a little extra effort on your part, sure, but technically doesn't cost you any further time spent.