Hi
I was about to send the template and then Gmail just pointed me at the fix:
When creating an empty file and just saving without touching anything else, Word does not save anything into the file (it is a 0 byte file).
I simply opened it, and just typed and erased a character, saved it, and BAM - the file was 13 kb in size. My code is now working nicely.
Thanks, sorry for the confusion, blame Microsoft for a fake Word file :)