A KNOWN ISSUE appeared in Build 49 is related to Backgrounds disappearing within a multipage cue (namely Lyrics) when editing the presentation. We have identified the cause and are working on a solution. However, the immediate workaround is to:
1) Select your Background image in the Edit Area
2) In the Ribbon, choose Object Visibility->Hide on All
3) Choose Object Visibility->Show on All
This will reset the Background to appear on all pages within the cue. Please call us if you have any issues with this.