avrdude: can't open input file C:\Arduino\arduino-1.5.1r2/hardware/arduino/avr/bootloaders/empty13Aat1.hex: No such file or directory
avrdude: read from file 'C:\Arduino\arduino-1.5.1r2/hardware/arduino/avr/bootloaders/empty13Aat1.hex' failed
Oops. Looking in the wrong root for the bootloader.
C:\Arduino\arduino-1.5.1r2/hardware/tools/avr/bin/avrdude -CC:\Arduino\arduino-1.5.1r2/hardware/tools/avr/etc/avrdude.conf -q -q -pattiny13 -cstk500v1 -PCOM6 -b9600 -e -Ulock:w:0x3F:m -Uefuse:w:{bootloader.extended_fuses}:m -Uhfuse:w:0xFF:m -Ulfuse:w:0x2A:m
"efuse" memory type not defined for part "ATtiny13"
Oops. Using the tools.avrdude.erase.pattern from the wrong platform.txt file.
I give up. I'll try again when 1.5.2 has been released.