Dear Igor,
regarding your recent problem: has it been fixed with the latest update?
When I pass set dbpath command on server start, it seems that the server sets the new value, but is partially ignoring it. [...]
I'm sorry, I didn't manage to reproduce this problem (on my computer, the database was created in the same directory as the log files). You may want to try the latest version here as well, or give us a more elaborate example that allows us to reproduce the issue.
Looking forward to your feedback, Christian