Arduino Fio and USB2Serial Light


I have Arduino Fio board from Sparkfun and USB2Serial Light (FTDI adapter) from Arduino. The Fio is running 3.3V and USB2Serial - 5V. My question is - can this FTDI adapter be used to program the Fio board? The official Arduino product page says it can (, I just would like to make sure...

And the similar question regarding Sparkfun Arduino Pro 3.3V/8MHz board.