ERROR: Unable to inject packet: list index out of range

[ElecsMani]

I got an issue like below any one help me this

zbstumbler: Transmitting and receiving on interface '/dev/ttyUSB0'
Setting channel to 11.
Transmitting beacon request.
Warning: waiting for serial read timed out (most likely).
Setting channel to 12.
Warning: waiting for serial read timed out (most likely).
Warning: waiting for serial read timed out (most likely).
Warning: waiting for serial read timed out (most likely).
Warning: waiting for serial read timed out (most likely).
Warning: waiting for serial read timed out (most likely).
Transmitting beacon request.
Warning: waiting for serial read timed out (most likely).
issue in peeking for a register
list index out of range
ERROR: Unable to inject packet: list index out of range

[Crypt0s]

Do you have the serial speeds set appropriately for the Goodfet API-Mote?