I sure can't replicate the issue in that demo page, but as you had the opportunity to see in my code sample, it's as barebones as it can get, and still I'm getting the Exception consistently.

Can't exactly figure out what's happening, but it seems to have something to do with how the file is persisted. What's odd about it is I've only managed to get the Exception with that specific file, and it has worked fine with many others.

 

Is there anything I can do to help track down this problem?