Warum sollte man den µC aus- und wieder einschalten müssen, um die Fuse bits permament zu setzen? Es reicht absolut, den Programmiermodus zu beenden. Dazu kann man den µC ausschalten, muss aber nicht.
Seite 224 ATMEGA8 Manual:
Latching of Fuses The fuse values are latched when the device enters Programming mode and changes of the
fuse values will have no effect until the part leaves Programming mode. This does not apply to
the EESAVE Fuse which will take effect once it is programmed. The fuses are also latched on
Power-up in Normal mode.