I can expand on this a bit. I spent last night working to get any kind of basic animation working using Blender -> .x -> XNA. I managed to do it using the following pattern: (disclaimer: I am using the
Animation Components Library with XNA 1.1, but the things that make importers barf are likely the same)
1. Create your mesh - start by keeping it simple, I started with nothing more than an extruded rectangular 'stick'.
2. Add your armature, then extrude a couple bones to fill the mesh. You might want to start with a mere two bones.
3. Name your bones something clear and easy to remember.
4. Once your armature is positioned in your mesh the way you want it, select your mesh, then begin assigning vertex groups. Make sure each group is distinct (no common vertices with other groups). Name the groups the exact same name as the bone to which you want them assigned. Leave each group's weight at 1.
5. Double check that every vertex belongs to a vertex group.
6. Double check that every bone has a parent (this messed me up a ton)
7. In object mode select your mesh, then shift-select your armature. Press Ctrl-P, select Armature, then select Name Groups. This will automatically assign your vertex groups to the appropriate bone so long as you've kept the names the same.
8. (continue to progressively save your work :P)
9. Put your armature into pose mode, and switch to your animation setup (I just use Ctrl-left arrow).
10. Setup your models initial pose at frame 1 and add a Loc/Rot keyframe for all the bones.
11. Do your animation - setting up keyframes and such as normal.
12. Reduce the total animation length to cover just the keyframes you added.
13. In the Action/IPO select box, with your full armature selected select Pose (I do this, but I don't know if its necessary)
14. With your full armature still selected, switch to the Action Editor in one of your windows, and select Keys -> Bake Action to IPO Keys. (You should get a little confirmation box saying a new action was baked. Click it.)
15. Save your work one more time.
16. Export your animation to .x using the following options: Animation checked, Speed checked, Flip xy (y up) checked, and Right-handed coords. Then just Export All.
17. Test your animation using the DirectX viewer. It should play correctly. If not (for example if things look really warped) then step backwards through your saved .blends and export them till you find one that works - then recheck your steps.
I then just play animation 0 using the animation components library - this works fine for me. Of course when you bring your animation into your project you need to remember to change the content processor and importers as appropriate - for me it's tht X File - Animation library importer and Model - Animation Library processor. If you have to use the skinned animation sample then I'm not sure what would need to be changed, but presumably the stuff in blender all still applies. Using this technique I managed to get (somewhat crude) humanoid meshes doing a walking animation with correct UV-textures. The most common problems I ran into that would mess things up were:
1. Missing a vertex.
2. Having a bone with no parent bone set (with the exception of the very first bone). This makes your model look wacky in the DirectX mesh viewer.
3. Forgetting to bake.
I hope this is useful. It's by no means extensive, presupposes some knowledge of blender, and is basically what I've learned after about a week of doing this.