Printrun issues with USB connection and OS X

I spent quite some time trying to get Printrun to connect my RAMPS board. The fix was to set the baud rate lower with #define BAUDRATE 115200 both in Marlin Configuration.h and in Pronterface user interface.

The screenshot below shows necessary details:

But the while I was testing some models there were long pauses in the print. Those were long enough to clog the hot end as the heating was on but no filament was pushed through. After couple attempts I started to use SD-card reader on the LCD display unit.