WowAce

What steps will reproduce the problem?
1. Begin combat with Atramedes in Blackwing Descent
2. Wait until Atramedes casts an ability that will generate sound

What is the expected output? What do you see instead?
Nothing.  LUA error.

What version of the product are you using?
v6.51

Do you have an error log of what happened?
Date: 2011-01-09 23:21:15
ID: 1
Error occured in: Global
Count: 11
Message: ..\AddOns\sct\sct.lua line 583:
bad argument #3 to 'string_format' (string expected, got nil)
Debug:
(tail call): ?
[C]: ?
sct\sct.lua:583: ?()
...Ons\Ace3\CallbackHandler-1.0\CallbackHandler-1.0.lua:147:
...Ons\Ace3\CallbackHandler-1.0\CallbackHandler-1.0.lua:147
[string "safecall Dispatcher[14]"]:4:
[string "safecall Dispatcher[14]"]:4
[C]: ?
[string "safecall Dispatcher[14]"]:13: ?()
...Ons\Ace3\CallbackHandler-1.0\CallbackHandler-1.0.lua:92: Fire()
Ace3\AceEvent-3.0\AceEvent-3.0.lua:120:
Ace3\AceEvent-3.0\AceEvent-3.0.lua:119

Still getting this today...

Date: 2011-06-14 22:47:36
ID: -2
Error occured in: Global
Count: 13
Message: ..\AddOns\sct\sct.lua line 583:
   bad argument #3 to 'string_format' (string expected, got nil)
Debug:
   (tail call): ?
   [C]: ?
   sct\sct.lua:583: ?()
   ...Ons\Ace3\CallbackHandler-1.0\CallbackHandler-1.0.lua:147:
      ...Ons\Ace3\CallbackHandler-1.0\CallbackHandler-1.0.lua:147
   [string "safecall Dispatcher[15]"]:4:
      [string "safecall Dispatcher[15]"]:4
   [C]: ?
   [string "safecall Dispatcher[15]"]:13: ?()
   ...Ons\Ace3\CallbackHandler-1.0\CallbackHandler-1.0.lua:92: Fire()
   Ace3\AceEvent-3.0\AceEvent-3.0.lua:120:
      Ace3\AceEvent-3.0\AceEvent-3.0.lua:119