You can disable the Auto Save by editing the nwn2player.ini
under [Server Options] add the line

Disable AutoSave=1

From my experience, if you have trouble with one area, you will continue to have trouble.
Do you have plenty of free space on your C: drive?
Did you right click on your Documents\Neverwinter Nights 2 folder right click> Properties> Security & see if your username has full control?
If you didn't disable your antivirus software before installing the game, I would download the June 2010 DirectX runtimes, to make sure you have 9.0C installed.
Save it to a temporary folder on your desktop & then run DXSETUP.exe, then delete the folder when you have finished.
See pic

i got the game in Gamersgate and in requirements it has this warning "WILL NOT WORK ON 64-BIT OS"
maybe thats why its giving you a hard time
No idea if the gog version is more user friendly but im glad im still using this old pc
patching to latest version helps a lot... sadly cant post link here for some odd reason but u search
neverwintervault.org/