OK I've done a little bit of trying stuff. I do have a CP2102 but it is a little old but I did get it to work (my settings page looks like yours). On looking at your model there was a thread about it (John was in the thread) and in that thread it was mentioned that the labeling was incorrect for the TX and RX (flipped). I don't know how you are hooking this up to your minis but I would stare really hard at how you have the TX and RX hooked up ( TX to RX and Rx to TX ) . Maybe a quick test is to hook up the TX line of the CP2102 thru a led -current limiting resistor-ground and see if there is activity on it when transmitting.
Here is that link: