Hello. I installed and configured the plugin perfectly in a linux server. Then I did exactly the same on a windows server and the following error shows up whenever I try to edit participants:
"FormElement::format_date: timestamp couldn't be formatted: 4 de julho de 2013
FormElement::format_date: timestamp couldn't be formatted: 4 de julho de 2013"
I'm using the exact same version of wordpress on both servers (official translation to pt_BR locale). It was setup from scratch in both servers, with the exact same steps and everything else appears to be fine.
Great plugin, by the way. Thanks.