I am thinking about upgrading my master server. Must I upgrade my media servers and clients also?

This Wiki is brought to you by Backup Central, where you can find the Mr. Backup Blog, Forums, and a mailing list for each forum!
Backup FAQs	Service Providers	Backup Software	Backup Hardware	Backup Book Wiki	Free Stuff	Miscellaneous

It's generally supported to have your clients one or two versions behind your master server and/or media servers. However, you obviously will not benefit from any new features that require an updated client.

Your master and media servers are a different story. If you're running 5.1 MP3 or greater, you can have your master server at one version and your media servers at another version. Prior to that, your master and media servers must be the same version.