Jaikoz also has the option in Preferences:Remote:Format:Multi Disc Releases that will take effect when matching from Jaikoz. But when manually tweaking you can edit the album field yourself.
Its not enabled by default since although it is MinimServer preferred way of doing things it breaks things in in other applications such as iTunes that expects the album name to be the same throughout. In fact MinimServer also expects album name to be the same apart from this (disc x of y) syntax that it allows at the end of the album name, I need to explain this more in a=my MinimServer blog series - http://www.jthink.net/songkongformelco/upnp.jsp
MinimServer can also identify multi discs if the Disc Subtitle has a value. The trouble is MinimServer uses this is in a non-standard way expecting it to have a value for any disc in a multidisc release. But to follow the standard this field should only be used if the disc actually has a title rather than just Disc 1, Disc 2 . But you could manually enter such data into Jaikoz if you wanted to instead of modifying the album title.