Are you experiencing problems with the object manager? You can take a look at the error log in the Eclipse workspace. The log is located here: "workspace/.metadata/.log". Maybe you need to first clean up the log and then reproduce the issue.
When you are using advanced configuration features like type handlers, special string encoding etc. you should add your configuration to the object manager.
Otherwise ask for help in the db4o forums. When you see errors in the log please include them in your post.