If I remember correctly, Flagfox doesn't work behind a proxy. (though NATs are fine) If you can, please PM me the gist of your company's network settings. Not sure if I can do anything about it remotely, however, but I can give it a shot.
Also posting here to announce that we're finally listed publicly on AMO.
Edited to add:
By the way, the WTS really isn't that smart... All of the in progress locales now show 100% or so, even though they're all blank strings. It seems the export with blank strings confuses the WTS on import back in. Probably because the strings are just empty, not missing. Whatever, as stated by Goofy, ignore the percentage.
Edited again to add:
I've done a little testing, and put myself behind a proxy. (with no access to DNS) In that case, I can get whatever the proxy can get, but Flagfox can't do a normal DNS lookup and stalls. It might be what you're getting. Lemme look into this a bit, though, if this is the case, then there's really no way for me to fix it. Flagfox needs DNS access to get the site's IP. Normally it just hits the cache, seeing as you've already gone to the website and have done a lookup. With a proxy, you haven't, so it does a new lookup which takes a while and fails.