I have a complete site with over 100 photos that takes up less than 30 Meg. That is a huge file.
Remember that upload speeds are a fraction of the download speed that is published for your internet connection. I suspect that it may simply be timing out.
I'm having the same problem with a flash movie.
.flv
is the free plan only allowed certain size files?
I have used 9 Mgof the 50Mg alloted and the file is 25Mg -- so there should be room for it.
also, my flash movies don't seem to want to work.