manbass - were you ever able to get this to work successfully? Your post got me intrigued so I loaded up edgesync on a laptop running Windows 7 ultimate x64. At first I experienced everything you did (the system.io.ioexception followed by and exception error when attempting to sync).
For the first error, I read somewhere that the previous version (0.5.1) did not have the error. I replaced my 0.5.2 install with 0.5.1 and that error did indeed go away.
The second error (and exception when trying to sync) seems to be an app error in the XML, but did not prevent the journal pages from syncing.
The last problem I had was that the pages, once loaded, were simply not converting to text. At first I thought this was an edgesync issue, but it would not even convert my handwriting on my laptop to text either. I have not really used OneNote much and had never thought to try that feature before. It turns out that I needed to go to my control panel/programs and enable the windows "tablet support." One reboot later and resync later I finally had handwritten notes converting to text.
I found OneNote a little picky about the size of the writing - if I was too big or too small it would not convert it. Edgesync, however, has a nice feature (in preferences) to change size of your pages when importing into OneNote - that helped.
I hope you can get OCR capability working!