I just tried it again and it worked this time. That is interesting: I don't know if they tweaked it a bit or not :), but I am feeling a bit better now, because my application really needs a reliable, accurate service like this.
No tweaking, promise :) It's possible you hit an inconsistent server first time around, I'll have a dig on our end. Let me know if you have any other problems - toby@textrazor.com.