We are copying the data from excel trying to paste it into pl/sql developer either to update a record or develop a query. We use the English version for the code around the Japanese, Chinese, etc. data.
The upcoming 7.0.3 version (beta available) will be Unicode compatible for viewing and editing the SQL Window result set. Version 7.0.2 requires an explicit national character set on the client.
We have noticed that the selected Grid Font (Tools > Preferences > Fonts) can be important. For example, Russian characters will not always display correct with MS Sans Serif, but will display correct when using Arial. You may want to try that.
If this does not help, can you let me know the following?
1. The results of the following query:
select * from nls_database_parameters
where parameter like 'NLS%CHARACTERSET';
2. Go to Help > Support Info, press the 'Copy all pages' button on this info screen, and paste this text into a topic or e-mail reply.