J-M-L:
Who wrote it there ? Does it has the weird byte(s) at the start in the first place ?
i make a txt file in my laptop,and paste it in the sdcard, then plug the sd card in w5100.
it doesnt have any wierd bytes ,its just a plain text.after the transfer,i checked the file in laptop,the date of the txt file didnt change.so that weird character comes during the transfer per byte.