A few things that might be causing issues:
- Don't export with spaces in the name of your oam file (or change the filename after export)
- Make sure the file size of your oam file isn't larger than the upload max size in your PHP settings. (More info: Troubleshooting OAM widget upload to Hype Animations Wordpress Plugin )
It should 'just work' -- can you share your Wordpress info with me so I can check it out? (You can PM me).