Are you using a USB hub or are you plugged directly into a USB port on your computer?

How many amps can your USB connection provide to the MoonLander?

Do you have a multimeter?  If so check the memory and core voltages.  Despite what It says on page 1, all four of my moonlanders are much more stable with the voltages set at .907 running at 924Mhz..

Also try speeding up your com port,   the default speed is 9600bps which is painfully slow.  I set mine to 38,400.