1 of 2 joined meshes disappears when background is displayed

[davefer]

Hi all -

I'm a noob to Blender and 3D modelling, but need to learn to use it professionally.

I've created a model that is an M&M -- an elipsoid with a text 'm' on its face.

I've converted the text to a mesh and joined it to the elipsoid mesh.

I export it over to an XNA project and display it rotating just fine.

But as soon as I add a background sprite, the text mesh disappears. The elipsoid mesh still displays fine, just the text mesh disappears.

I've tried every different type of BlendState (XNA), to no avail.

I can't think of what else to vary. I know this works, I did this same project 2 years ago (but since then, I've lost all my models).

Any suggestions?

Thanks!

- Dave Ferreira