Anybody has experience installing the FTDI driver on the native PogoPlug?

I copied ftdi_sio.tar to /tmp folder and extracted to a subfolder. Then I tried to "make" but it says init.h file is missing.

Then I obtained ftdi_sio.o file online and try to "insmod ftdi_sio.o" but failed. It says "Invalid Module Format"

I have a device with FTDI chip and I want to let PogoPlug recognize it and show it as ttyUSBX under /dev folder.

Thanks in advance!

zhaozh