[cflsystems]

The module has serious bug - only "all" customers are allowed to leave testimonial. If set for "registered" only no one can leave testimonial.
The module sets this when it is being initialized using $login variable. At the same time $login variable is being set after all modules are loaded and initialized. So the $login is always empty at that stage and the module will not allow testimonials if set to "registered customers only".

Needs bug fix asap...