Richard, no idea what actually is happening, but >iccavr -c -I../include -Ic:\icc/include -e -DATMEGA -D_MCU_enhanced -DETHERN >UT2 -l -Mavr_enhanced -I../mod/include -I../include fat.c shows, that you are using the new nutconf setting for Ethernut 2, but you got Ethernut 1.x for sure. Regards, Harald