I had the same problem and it was drivin me crazy. Then, for some reason I removed the spaces before and after the pathnames, ie instead of #include < avr/io.h > I tried #include <avr.io.h> and the problem went away! I hope this helps 
danno
I had the same problem and it was drivin me crazy. Then, for some reason I removed the spaces before and after the pathnames, ie instead of #include < avr/io.h > I tried #include <avr.io.h> and the problem went away! I hope this helps
danno