PT BIO Grims:Hello there!
Had you received any news on the subject Aztec? I'm in the same situation... I want to participate in the dreambuildplay.com event, but I use .xsi content and we must submit in 3.1 version, right?
Thank you for your attention!
PT BIO Grims
Unfortunately I haven't heard anything on this issue.
My solution since there is only a few weeks left was to just go ahead and make make my animated models in blender. It is difficult because the interface is just terrible compared to xsi, but the animated models work perfectly with xna.
I am however still creating all static models inside xsi as the .fbx exporter seems to work just fine for non animated models.
So I guess for now, you have to just switch back and forth.