What steps will reproduce the problem?
1. Enter Naxxramas

Do you have an error log of what happened?
[2009/01/04 20:35:07-1185-x1]: LibBabble-Zone-3.0-90170:65: LibBabble-Boss-3.0: Translation "Deathknight Understudy" not found.
...gs_RazuviousAssistant\BigWigs_RazuviousAssistant.lua:19 in main chunk:
<in C code>: in function `LoadAddOn'
BigWigs-2.0 r4842\LoadOnDemand.lua:34 in function <Interface\AddOns\BigWigs\LoadOnDemand.lua:26
BigWigs-2.0 r4842\LoadOnDemand.lua:227 in function <Interface\AddOns\BigWigs\LoadOnDemand.lua:204
<in C code>: ?
AceEvent-2.0-91091 (Ace2):298: in function `TriggerEvent'
BigWigs-2.0 r4842\Core.lua:399 in function <Interface\AddOns\BigWigs\Core.lua:395
<in C code>: in function `pcall'
AceDB-2.0-91091 (Ace2):24: in function <Interface\AddOns\Ace2\AceDB-2.0\AceDB-2.0.lua:23
AceDB-2.0-91091 (Ace2):1863: in function `ToggleActive'
BigWigs-2.0 r4842\LoadOnDemand.lua:249 in function <Interface\AddOns\BigWigs\LoadOnDemand.lua:238
<in C code>: ?
AceEvent-2.0-91091 (Ace2):298: in function `TriggerEvent'
BigWigs-2.0 r4842\LoadOnDemand.lua:260 in function <Interface\AddOns\BigWigs\LoadOnDemand.lua:255
<in C code>: ?
AceEvent-2.0-91091 (Ace2):298: in function `TriggerEvent'
Roster-2.1-90093 (Aloft):225: in function `ScanFullRoster'
Roster-2.1-90093 (Aloft):112: in function <...nterface\AddOns\Aloft\Libs\Roster-2.1\Roster-2.1.lua:106
<in C code>: ?
AceEvent-2.0-91091 (Ace2):260: in function `TriggerEvent'
AceEvent-2.0-91091 (Ace2):925: in function <Interface\AddOns\Ace2\AceEvent-2.0\AceEvent-2.0.lua:923
<in C code>: ?
AceEvent-2.0-91091 (Ace2):368: in function <Interface\AddOns\Ace2\AceEvent-2.0\AceEvent-2.0.lua:345