Sorry for the slow response on this, I've been away on holiday for 6 weeks.
First off which version of Face-to-face are you using. There is the version that is on the plugins page and also a version that can be downloaded from Github. The bug you are encountering should be fixed in the version on Github. I am in the process of fixing a few issues that came up with changes in Moodle 2.3 and hopefully will get a new version onto the module plugin page within the next week.