@astrobeed ho provato con il toolchain atmel modificato da te ma ricevo comunque l'errore su delay ed altro...
In file included from C:\Documents and Settings\Administrator\Documenti\arduino-1.0\hardware\arduino\cores\arduino/Platform.h:9:0,
from C:\Documents and Settings\Administrator\Documenti\arduino-1.0\hardware\arduino\cores\arduino\CDC.cpp:19:
c:\documents and settings\administrator\documenti\arduino-1.0\hardware\tools\avr\bin../lib/gcc/avr/4.5.1/../../../../avr/include/util/delay.h: In function 'void _delay_ms(double)':
c:\documents and settings\administrator\documenti\arduino-1.0\hardware\tools\avr\bin../lib/gcc/avr/4.5.1/../../../../avr/include/util/delay.h:149:42: error: 'fabs' was not declared in this scope
c:\documents and settings\administrator\documenti\arduino-1.0\hardware\tools\avr\bin../lib/gcc/avr/4.5.1/../../../../avr/include/util/delay.h:149:43: error: 'ceil' was not declared in this scope
c:\documents and settings\administrator\documenti\arduino-1.0\hardware\tools\avr\bin../lib/gcc/avr/4.5.1/../../../../avr/include/util/delay.h: In function 'void _delay_us(double)':
c:\documents and settings\administrator\documenti\arduino-1.0\hardware\tools\avr\bin../lib/gcc/avr/4.5.1/../../../../avr/include/util/delay.h:226:42: error: 'fabs' was not declared in this scope
c:\documents and settings\administrator\documenti\arduino-1.0\hardware\tools\avr\bin../lib/gcc/avr/4.5.1/../../../../avr/include/util/delay.h:226:43: error: 'ceil' was not declared in this scope