How did you wire your seeeduino up to the rainbowduino? Does it show below?
Seeeduino Rainbowduino
13<-----------SCK
12<-----------MISO
11<-----------MOSI
10<-----------RESET
5V<-----------VCC
GND<----------GND
I did follow your guide and get the result:
avrdude: safemode: lfuse changed! Was ff, and is now 0
Would you like this fuse to be changed back? [y/n] y
avrdude: stk500_cmd(): programmer is out of sync
Now I have to doubt there is hardware problem with the rainbowduino.
Thanks again!