The new version, 0.61, claims to fix the 'bug' that caused a private torrent to be shared freely. Change log v0.61:

- GUI Improved: enhance BCTP link command to lunch preview window
- GUI Improved: support xp themes in the embedded browser
- GUI Improved: no longer popup script error message in the embedded browser
- GUI Bugfix: Possible buffer overflow when opening URL link using external browser.
- GUI Bugfix: the clip board can work in some user interface
- Core Improved: support wmv/asf file in the preview window
- Core Bugfix: fix the bug that DHT is added for the 'private' torrent after task begins
- Core Bugfix: fix the bug that UDP port mapping is not released when bitcomet exit

Download BitComet v0.61 here.