filenames with non-english characters

Thank you for the very nice installer.
I have installed “bitnami-alfresco-2.9.0B-1-windows-installer.exe” and everything seems to be working fine, except when I upload files with greek characters they display as i.e ???.doc. I have changed the charset and collation in MySql (ALTER DATABASE bitnami_alfresco), but this does not seem to fix the problem.
Also, according to a forum post I have found the file “C:\Program Files\BitNami Alfresco Stack\apache-tomcat\shared\classes\alfresco\extension\custom-repository.properties.sample” saved it to custom-repository.properties and changed lines 40 and 41 to

db.driver=org.gjt.mm.mysql.Driver
db.url=jdbc:mysql://localhost/alfresco?useUnicode=true&characterEncoding=utf-8

Edit
I found another custom-repository.properties in “C:\Program Files\BitNami Alfresco Stack\apache-tomcat\webapps\alfresco\WEB-INF\classes\alfresco\extension\”. There I edit the db.url as
db.url=jdbc:mysql://localhost:3306/${db.name}?useUnicode=true&characterEncoding=utf-8

after this, when I upload a file with non English characters I get JDBC Exception on Hibernate data access: nested exception is org.hibernate.exception.GenericJDBCException: could not execute query. End Edit

This does not seem to solve the problem either.NOTE: after each change I have restarted the service.

Thank you for your help and effort.

Chris