David, have you tried playing with the various Data representation elements that you can specify to try to debug this? For example it appears that one can just import the first frame -- that could give you a sense of what's going on. Also the different frames can be imported as a list of graphics, an amimation, or a list of images...   You probably know that but in case not... 
--David

P.S.  Feel free to send me the example and I will play with it to see if I have the same behavior as you.  You have my email from my LinkedIn profile...