Twitch,
There was a bug with the first release but that should be fixed with the latest dot release... one thing I have had to do a couple of times is press the tab or return key after setting the default file to ensure that it sets in the dialog box. If you cannot get it to work, you could edit the default file property manually, inside the code. But again, try updating it again and hitting either tab or enter inside the input box and see what happens.
Regards,
Brian