I played a nec protagonist, but didn't see vocalize in the loot after beating shadow dragon, found only infravision instead. Loaded several times yet keep getting the same result, it never really happens before... Is this a new feature of 6.4, or just a rare bug? Btw, I can't find scroll of vocalize in eekeeper any where.

Did you import the protagonist from BG1, by any chance?

I didn't. Btw previous to shadow dragon I looted ghost amour in pirate's hideout as usual, it seems the problem is on shadow dragon itself. The good news is amulet of hades is available using EEkeeper, so it only matters if shadow dragon should drop vocalize scroll...

Strange. Could you tell me if the protagonist cre file (inside the save game) has any effects that set scripting states?

Type: Script: Scripting State Modifier [282]
Value: 6
Resource 3: SPCIL11
Time: 0

Well, that's double weird. Everything should work well enough. Could you send me the save file to inspect?

You can also check whether the LOCALS variable Iatreasure3 is set to 1 when you're inside the Shadow Dragon's lair.

Two new bugs I faced:
1,Protagonist is qualified, should be 100% a success, yet it turns out I didn't receive robe of apprenti though dialogues were normal as before, indicating I should have received one.
2,The truth can't be equipped by anyone. Neither neutral-good kensai nor Valygar can equip, and when I loaded it with DLTCEP to check, even evil character is allowed to equip it, how strange.

Well, the truth has equipped ability that only cernd can use it.

The Truth is fixed in the latest build (found on github, links here http://forums.blackwyrmlair.net/index.php?showtopic=5326).

Send me a save game, please, to inspect the other issues.

Sure, what's your email, or any other contact through which I can attach my save?

I cannot compress my save to within 128k...

PM'ed you the address.