problem making animation w/ avmotion - possible bug?

I am pretty new to making animations, & it's quite possible that I'm just missing something, so bear with me.

I made, or attempted to make, an animation in which the avi's arms are raised in the air; it looks the way I wanted it to when playing it in Avmotion, but when uploading it to sl, the arms rest down by the sides of the avatar... no idea why this is happening. Am I doing something wrong, or is it just an imperfection of Avmotion itself?

Did you raise the arms in the second frame or so? I am new to the program as well but I found leave frame 1 as it is (default position) and then do the motions in frames after that and it worked for me. Sorry if this was not a help, but thought that might be the issue.