Zolt,
The reason you still don't see any match is probably because the string you enter in the quick search does not match any of the rows in the result set displayed in DbVisualizer.
You should probably look into the "Where Filtering" feature which is used to limit the rows on the server side via a where clause. Read more here:
http://www.dbvis.com/products/dbvis/doc/main/doc/ug/databaseExplorer/databaseExplorer.html#mozTocId906372
This is also much better from a performance view since only the rows you are looking for will be handled.
Regards
Roger