Check your WTF SavedVariables folders for .bak versions of files. They are only made every so often, but if you've had your UI for as long as you say you have, it might be worth a shot.
Also, Windows (Vista and higher) keeps copies of files' previous versions for indexed folders (possibly for others too). Try checking of Right Click->Properties->Previous Versions shows anything.
---------- Post added 2011-12-05 at 07:48 PM ----------
Oh yes, and I recommend you schedule an automated backup script to avoid future incidents. I use the following .bat file:
Code:
@echo off
SETLOCAL
SET file=%DATE:~3,2%%DATE:~0,2%%DATE:~-4%-%TIME:~0,2%%TIME:~3,2%
%TIME:~6,2%
SET wowdir=D:\World of Warcraft
SET bakdir=D:\wtfbak
cd /D "C:\Program Files\WinRAR"
rar a -r- %bakdir%\wtfbak-%file%.rar "%wowdir%\WTF\Config.wtf" & rar
a %bakdir%\wtfbak-%file%.rar "%wowdir%\WTF\Account\STOLENLEGACY"
ENDLOCAL
Replace the values in the SET lines as appropriate, as well as the ACCNAME placeholder. You can also use task scheduler to run this frequently.