Based on the files replaced, the build numbers and the issues fixed its a cumulative update and therefore, as seen before, replaces the October 19, 2006 hotfix package dubbed KB 926404 and all the earlier updates.
Interestingly it fixes an "issue" I have seen at a customer where the custom help link wouldn't launch unless it was part of Trusted Sites zone in Internet Explorer (Which can be/is an issue in global deployments of LCS, where clients aren't centrally managed).
New fixes are -
- A custom help option that uses a fully qualified domain name does not work in Communicator 2005
- An access violation error may occur when you try to exit Communicator 2005
And the old fixes still included are -
- Error message when you try to use Communicator 2005 to log on to Live Communications Server
- Communicator 2005 does not start on a Windows 2000-based computer
- Communicator 2005 contact list may incorrectly list a contact as "Status unknown"
- Your telephone calls are not forwarded after you sign in to Communicator 2005
- Some of the audio control buttons are missing when you resize the Conversation dialog box to its minimum size in Communicator 2005
- A contact cannot be found in Communicator 2005
- A short delay is experienced before music or a voice message is heard in Communicator 2005
- Advanced VoIP calling features are unavailable in Office Communicator 2005
- The status indicator may incorrectly display the Away status for your presence status in Communicator 2005
- Communicator 2005 may quit unexpectedly when it tries to retrieve the free/busy information from an Outlook calendar
- You can use a copy-and-paste operation to transfer the contents of a file when a policy that disables file transfers is applied to a computer that is running Communicator 2005
- Internet Explorer unexpectedly closes when you refresh a Web page
A telephone number may contain a clock icon instead of the number zero in Communicator 2005
- Error message when you try to shut down Windows: "End Program-WMS Idle"
- You experience poor video quality in Communicator 2005 running through a multipoint control unit
- Communicator 2005 responds to invitations to conversations with a "Busy" reply