Hi. I just bought FM4 today and before doing so, was able to test (with the trial version) putting a RTFD onto a slide to use as a background for a title, and it worked fine.
With the paid version, I now find myself unable to drag an RTF file onto a slide (update: I do see the trial version and app store version are the same revisions). I get a thin white placeholder that appears to be empty regardless of who much I zoom. My rtf file is the same I used in the trial version of FM, and I’ve created 4 others in an attempt to make this work.
I can workaround by creating a title background in pixelmator, but it was easier working with text in Pages or Text Edit.
Are there any other ways of creating background for titles? I’ve only use FM for 3 days, but I don’t see a way to do so natively in the app.
thanks, attached image of what I see
I can confirm what BrunoSardine is seeing – something is glitchy here 
(I don’t recall this occuring in earlier versions.)
I’ve requested before that text “boxes” have the ability to acquire background (or shall I say “fill”) colors while the text itself is a different color, that the background color can have opacity values from 0% to 100%, and that a background color can be a gradient from one percent to another of the same color, either horizontally or vertically, or to have a gradient from one color to another color. I’d also like to see the text “box” be given a “border” of whatever color and pixel width the user enters.
I believe I requested that sometime last year, but so far I haven’t seen it happen – yet.
As an afterthought – but I realize you already figured out a work-around – create your “background” in a 3rd party app and then import it onto your slide, then place the text on top of it. By creating a large enough “background” that is sized universally to fit your slide show, use the new mask feature to size the background any way you want.
I did do this with a gradient background created as a .png file in Photoshop with a transparent background (so my slide showed through). Aside from being inconvenient in having to go outside of FM is that it takes up one layer on the slide. Depending on what you plan on doing, that single layer can be priceless – then you’re stuck.
@BrunoSardine: Please can you provide the RTFD you have trouble with?