PirateWalla login error

I have been using PirateWalla for a couple of weeks and think that it's a really nice iPhone app. :-) But, yesterday when I started the app. in my iPhone, i got an error message: "Shenanigans (you might want to check that you've got a valid GoWalla user name)". I tried it on my iPad 2 but got the same error message. I have only entered my user name in the PirateWalla app. once and have never changed it. What could be the problem here?

/Kristian