If you have signed up to the Microsoft Online services and have included Live Meeting in your subscription you may have problems connecting to other live meetings organised outside of the Microsoft Online servers (e.g. meetings with Microsoft).
The problem as I understand it is that the single sign-on client sets some default account and server options that direct the live meeting client to the Microsoft Online servers, and these prevent pass through or redirect to the hosting server.
The problem you get is the client fails to contact the live meeting server requesting that you install a different version of the Live Meeting Client.
Install a Different Version of Live Meeting Client
The version of the Live Meeting client is not compatible with the server.
Fortunately you do not actually need another version, you just need to remove the configuration setting that the Single Sign-on client provided. I recommend you make a note of these in case you need them in the future.
Fixing the Issue
Open the Live Meeting client from the start menu and click the menu in the top left (as below) and choose Open User Accounts.
Clear the sign-in name and URL, it you end up looking like the image below.
Click on the advanced button and uncheck the use these Servers.
Click OK and OK to confirm.
Close the client and you should be good to go.
To start new meetings you will need to do this from the Single Sign-On client (directed to the web) – or you could reset the properties.
Removoing the settings above means that you will be unable to use Office Communicator – so it will likely be a case of switching between the settings until Microsoft can resolve the issue properly.