Like many others I've had problems getting PRO MINI boards working reliably with the external USB FTDI Basis Breakout.
I even have the problem using a UNO board as the USB / 232 interface to a PRO MINI.
I've just ordered some PRO MICRO boards which feature an inbuilt USB interface. Has anyone had the old "not in sync" problem with this board? They are also on ebay for approx $5 out of ASIA so compete well with the PRO MICRO in price.
But then if none of these mini boards work then I'll just have to continue with the good old UNOs which only cost $10-$12 again on ebay.
All of the ongoing posts re the sync problems should maybe written up as a sticky post.