From valued forum member Avrin's topic, SonicStage 4.3 "Ultimate" Release 2:
Since the "Ultimate" 4.3 version seems to have gained quite a popularity, and appears to be less glitchy than any previous one, I decided to build a second release. This is purely a cosmetic update.
What's changed from the first release:
1. Updated Registry Information Setup is used now. This doesn't affect minidisc functionality in any way, but may add support for some newer ATRAC phones (you still need to provide the respective drivers).
2. The link to Minidisc Community Forums in the Help menu is replaced with a link to Sony Insider Forums.
3. Installation package extraction path is no longer saved to registry.
4. Windows Installer 2.0 distribution package is not included.
The complete list of changes from the official VAIO version (including changes introduced in the first release):
1. System prerequisites from Microsoft (Windows Installer 2.0, DirectX 9.0c, Windows Media Format 9, Windows Media Format 9.5, Data Access Components 2.5) are not included.
2. OpenMG Secure Module version 5.0 with the respective Registry Information is used instead of the original patched version 4.7.
3. Sony CONNECT Store support is no longer installed.
4. SonicStage Security Update is installed automatically.
5. Latest Personal Audio Drivers for SONY devices are installed automatically.
6. The VAIO support link in the Help menu is replaced with a link to Sony Insider Forums.
NOTE: If you have applied the experimental SonicStage patch 4.3.02 for Vista/Windows 7, you'll need to re-apply it after installation.
NOTE 2: If you need NetMD, you will probably have to install one of the drivers in the downloads section, as the older drivers have some different problems. In particular, if (as for many people) the system is Windows-64-bits, you will need the driver NETMD760, and you will need to undo some of the drivers installed by the SonicStage setup. If you have an MZ-RH1, you are especially warned to install that driver or its 32-bit cousin NETMD052.SYS (also under downloads) on every NetMD device.