Part of the problem is the compound shapes. Flash *really* does not like the compound shapes Moho exports. (Compound shapes are those with either holes or where there are multiple shapes filled as one.)
Text definitely fits into this category. When you create a text object in Moho, all the letters are filled in as a single shape. The Flash player doesn't mind this, and displays it properly. Unfortunately, the Flash authoring tool doesn't like it.
Unfortunately, there doesn't seem to be a fix. If Macromedia's two programs can't even decide how to consistently display Flash files, it's unlikely that Moho will be able to create such shapes to satisfy both of them.