First, thanks for your great work! Your plugin is awesome, it's cool game for autosport sites!
On my site plugin works sometimes not correctly. I use WordPress 2.9.2 + BuddyPress 1.2.1 + Motor Racing League 1.1.2.
Some registered users can not make a prediction for the race. After submitting filled form system shows message "You must be logged in" although user is authorized.