Ubuntu 12.04 LTS 64-bit
Kernel Linux 3.2.0-24-generic

Almost every time I initiate dialogue with someone, either in-game or in cutscenes, the dialogue hangs and doesn't advance properly. In-game this means that when I talk to a character, it takes a good 10-20 seconds for their response to be heard. In cutscenes this means that there's an awkward pause after every line where the character just stands there staring until a long time passes or button is pressed to advance it manually.

There are also a few non-dialogue things that hang as well. When I pull up a deep arrowhead with the dowsing rod, it takes an unusually long time for the dowsing rod to become active again. Until it comes back online, the energy bar on the left stays at the top and the dowsing rod is not illuminated at all.

Here is my terminal output when I'm talking with Ford in his lab:

Anim: anims\dartnew\talk_2.jan: loaded (1 frames latency)
Game: Engine Saved[CA]: Dialognode1_20Cleared = 1
ERROR: Can't load a null sound.
Anim: anims\janitor\camtutorial_talk1.jan: loaded (1 frames latency)
ERROR: Can't load a null sound.
ERROR: Can't load a null sound.
Anim: anims\janitor\talk2.jan: loaded (1 frames latency)
ERROR: Can't load a null sound.
Anim: anims\janitor\talk1.jan: loaded (1 frames latency)
ERROR: Can't load a null sound.
ERROR: Can't load a null sound.
ERROR: Can't load a null sound.
ERROR: Can't load a null sound.

And here is my output in one of the Sasha cutscenes before entering the brain tumbler:

Game: Engine Beginning cutscene CASA6EnterTumblerLastTime
Game: Engine Cutscene progression: CS Script moving from state nil to state ___EZScene, resultant state ___EZScene.  Time: 462.9795227050781.
* Stack Trace
1: setState                  (line   -1, file '(none)) (field)
2: xRunCutsceneWithSettings  (line   -1, file '(none)) (field)
3: runCutsceneWithSettings   (line   -1, file '(none)) (field)
4: runCutsceneWithSettings   (line   -1, file '(none)) (field)
5: runCutscene               (line   -1, file '(none)) (field)
6: (null)                    (line   -1, file '(none)) ()
Game: Engine starting proc action table 462.9795227050781
Game: Engine done proc action table463.3415832519531
Game: Engine starting proc action table 463.3415832519531
Game: Engine done proc action table463.4192199707031
Game: Engine starting proc action table 463.4192199707031
Game: Engine done proc action table467.7335510253906
Game: Engine starting proc action table 474.4738159179688
Game: Engine done proc action table474.4738159179688
Game: Engine starting proc action table 474.4738159179688
Game: Engine done proc action table474.5775451660156
Game: Engine starting proc action table 474.5775451660156
Game: Engine done proc action table475.5998229980469
Game: Engine starting proc action table 477.1417541503906
Game: Engine done proc action table477.1417541503906
Game: Engine starting proc action table 477.1417541503906
Game: Engine done proc action table477.2500915527344
Game: Engine starting proc action table 477.2500915527344
Game: Engine done proc action table485.18896484375
Game: Engine line skip requested, skipping.
Game: Engine starting proc action table 489.5285339355469
Game: Engine done proc action table489.6300964355469
Game: Engine starting proc action table 489.6300964355469
Game: Engine done proc action table497.5948791503906
Game: Engine starting proc action table 508.6642761230469
Game: Engine done proc action table508.6642761230469
Game: Engine starting proc action table 508.6642761230469
Game: Engine done proc action table508.767822265625
Game: Engine starting proc action table 508.767822265625
Game: Engine done proc action table511.8863525390625
Game: Engine starting proc action table 516.3892822265625
Game: Engine done proc action table516.3892822265625
Game: Engine starting proc action table 516.3892822265625
Anim: anims\dartnew\gesture01.jan: loaded (1 frames latency)
Game: Engine done proc action table516.4796142578125
Game: Engine starting proc action table 516.4796142578125
Game: Engine done proc action table524.7871704101562
Game: Engine starting proc action table 535.6246948242188
Game: Engine done proc action table535.6246948242188
Game: Engine starting proc action table 535.6246948242188
Game: Engine done proc action table535.7227783203125
Game: Engine starting proc action table 535.7227783203125
Game: Engine done proc action table539.3964233398438
Game: Engine starting proc action table 544.5008544921875
Game: Engine done proc action table544.5008544921875
Game: Engine starting proc action table 544.5008544921875
Game: Engine done proc action table544.5975952148438
Game: Engine starting proc action table 544.5975952148438
Game: Engine done proc action table547.4793701171875
Game: Engine starting proc action table 553.2305908203125
Anim: anims\sasha\gesture_concerned.jan: loaded (1 frames latency)
Game: Engine done proc action table557.9261474609375
Game: Engine Cutscene progression: CS Script moving from state ___EZScene to state CleanupCS___EZScene, resultant state CleanupCS___EZScene.  Time: 557.9261474609375.
* Stack Trace
1: setState                  (line   -1, file '(none)) (field)
2: (null)                    (line   -1, file '(none)) ()
WARN: (none(-1) SetEntityFlag ca.CASACutscenes: argument 3 is nil (not a number)
Game: Engine proccing end action table
Game: Engine starting proc action table 557.953125
Game: Engine done proc action table558.1319580078125
Game: Engine done proccing end action table
Game: Engine Ending EZ cutscene CASA6EnterTumblerLastTime (currCSName ___EZScene)
Game: Engine RESTORE SECONDARY TARGET
Game: Engine SET SECONDARY TARGET nil
Game: Engine ERROR: EZSceneThread still remaining in table on cutscene end, in state: nil
Game: Engine Saved[CA]: bCASA6EnterTumblerLastTimePlayed = 1
Game: Engine Cutscene progression: CS Script moving from state CleanupCS___EZScene to state nil, resultant state nil.  Time: 558.1577758789062.
* Stack Trace
1: setState                  (line   -1, file '(none)) (field)
2: endCutscene               (line   -1, file '(none)) (field)
3: (null)                    (line   -1, file '(none)) ()
PSYCHONAUTS UNIX FILENAME: corrected 'WorkResource/cutscenes/prerendered/cani.bik' to 'WorkResource/cutscenes/prerendered/CANI.bik'
PSYCHONAUTS UNIX FILENAME: corrected 'WorkResource/cutscenes/prerendered/cani.bik' to 'WorkResource/cutscenes/prerendered/CANI.bik'
PSYCHONAUTS UNIX FILENAME: corrected 'WorkResource/cutscenes/prerendered/cani.bik' to 'WorkResource/cutscenes/prerendered/CANI.bik'
WARN: ENGINE: Lua garbage collection starting
FreeUnusedBlocksInBuckets released 0 Kb
Game: Engine Saved[GLOBAL]: bNIPhaseThreeEntered = 1
WARN: (none(-1) StopSound LevelScript: Warn: LSO LevelScript does not have an entity