guilherme_ebio:
Yes, a use the Ethernet to browse the files on the SD card, and see the files, and i use an keyboard and some info to save the data to the SD card, like the date and the sector chosen, etc, so when a start the arduino i can see the files and browse then, but after a used the keyboard to save new data on the SD the error occurs, it's not all the time but it happens a lot.
I'm sorry, but I'm still not clear what you mean. Does "keyboard" mean "PC"? Where does "ethernet" come into this? I think you need to explain in more detail what your solution consists of and what sequence of actions you go through to cause the problem, and to avoid it.