I recently destroyed the chip in my diecimila with a voltage spike and decided to replace it with the ATMEGA328 with bootloader already burned by Sparkfun. After popping the new chip in and changing the board under tools in the IDE, I now get this message when trying to upload to it:
avrdude: stk500_recv(): programmer is not responding
when you press the reset button, the L LED should flicker briefly, then shut off. It will remain off for about 6-8 seconds; this is the period during which the bootloader on the ATmega8 is waiting for a new sketch to be uploaded from the computer
Do you see the same behaviour?
Try to perform an upload just after pressing the reset button. Does that make any difference?
I remember having to use that trick with my Lilypad, but in this case the L LED doesn't even light up. I have no idea what's going on here. Will have to have my local gurus take a look at it.