Behavior:
On an oracle system words with special characters (language dependent) are stored. The words are displayed correctly in the client. But when you search for the words with special characters you get no result.
Solution:
The NLS_LANG key has to be adapted to the correct language in the registry on following path:
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\ORACLE\KEY_OraClient11g_home1_32bit
For more information about NLS_LANG key please refer to following link:
http://www.oracle.com/technetwork/products/globalization/nls-lang-099431.html#_Toc110410543