Error message when exporting animated model

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Open my very simple rig, footrig.blend
2. File > Export > XNA FBX Animated Model (.fbx)
3. Save

What is the expected output? What do you see instead?
I expect no error.
I get an error message which include the following:
TypeError: 'tuple' object does not support item assignment
location:<unknown location>:-1

What version of the product are you using? On what operating system?
Blender 2.56.0
I've tried both the included exporter and the 2.56a patch
Windows 7 

Please provide any additional information below.
I am quite new to both blender and XNA, and would not be surprised if I'm doing 
something stupid.  Once exported, the .fbx loads in XNA, but only includes the 
bone "RootNode" in Model.Bones[].

Original issue reported on code.google.com by Albert.B...@gmail.com on 7 Feb 2011 at 5:08

Attachments:

• footrig.blend

[GoogleCodeExporter]

As suspected, I'm still learning things.  Seems I can no longer recreate the 
error.  I think it may have had to do with the way I saved things.

Original comment by Albert.B...@gmail.com on 7 Feb 2011 at 8:07