dcat the last thing you described looks like a bug... but i think that we need a sample (a .sla) and exact steps to reproduce to judge...
OK..I'm attaching 2 files for the interested to try to reproduce my bug. One is the "start" file: no master pages. The other is with master pages and the problem I'm seeing.
Steps to produce the Bug:
1. Begin with a document with some content and one non-master page. graphic and type. My type is in the top left corner. My background is a regular gray made in Scribus.
2. Either duplicate the start page, or type some variation of the Type. In my example, I start with the type saying Category. My variations are Category One, Category Two, etc.
3. After each type variation, Choose: Page > Convert to Master Page... when presented with a naming box, name the master page something to differentiate from the other.
4. Rinse and repeat for a couple variations.
5. Open Edit Master Pages palette. Click once on one of the master pages, then on others. If you precipiated the bug, one or more of the master pages' type which you varied will not be visible. You will instead see what I believe is an Overflow X where the bottom right corner of the text's box is.
6. Exit Master page palette. Insert new blank page, and begin applying the Master Pages you created to that new blank page. One or more should produce a page with the type not visible, but with the little X visible where that text's bottom right corner is.
For extra fun, see whether moving the type boxes on each master makes that text visible. Put it back where it was, it disappears.
Also, on the masters where the text is not visible, move that item to the top layer. Becomes visible. Go to another Master, then back. The text you just made visible is again not visible.
Thanks for proving/disproving this bug.
dcat