jrburke99:
The driver was downloaded directly from the Prolific website.
That doesn't mean anything. The Arduino Uno driver is a good example. It can be downloaded directly from this site but the kernel driver is Microsoft's.
In PuTTY, I get the same thing where I see nothing when I type, although I see the TX and RX lights on the board blink when I type.
As far as I can tell, that proves the kernel driver is the culprit.