After reaching General Tso's Chicken, Ratbeard's voiceover is missing before General Tso speaks. It appears there's a few more missing voiceovers than anyone can find. If anyone else finds any more missing voiceovers, please report! Thanks for correcting problems and listening!
This may have been documented already but Jack's dialogue for completion of The Claws of Justice appears to be bugged. You can hear the voice over, but the subtitle cards only display for the quest complete dialogue.
Also, the LAAAMMMP... MIIIINE voiceover for the Witch Doctor in the quest Here Comes Trouble appears to be missing.
And it it may be me rushing the Troggies too quickly, but the chances of getting the dialogue before the Defeat The Troggies In the Flooded Shrine fight (Quest: Into The Skull Cave) is about fifty - fifty.