When i launch lfs PitSpotter, all seems fine, but then it says :

inSim : First byte in packet does not match size

Is there anyone out there who can help me with my problem???

Write black, thanks.

As far as I know PitSpotter is out of date and no longer being updated. Go to this link for LFSRelax which has pitspotter incorporated into it.

http://www.lfsforum.net/showthread.php?t=27913