Hi I have built a mighty-1284 on breadboard. I have installed in my linux box the folder mighty-1284 from maniacbug's .zip file.
I open arduino 1.0 ide and selected optiboot_atmega1284 after some seconds my avr programmer ( pololu avr usb programmer that i have added to programmer.txt) blinks and copy bootloader to 1284p ..I hope 
arduino ide return with no errors. Well ...next step....so I try to upload a blink sketch....but I have this error: avrdude: stk500_recv(): programmer is not responding 
how i can investigate? Is a problem to reset pin? I have folllow maniacbug instruction :D.
also i have tried with this command line
avrdude -c avrispv2 -p m1284p -e -P /dev/ttySA0 -U -e Ulock:w:0x3F:m -Uefuse:w:0xfd:m -Uhfuse:w:0xde:m -Ulfuse:w:0xff:m flash:w:/home/marco/Desktop/arduino-1.0/hardware/mighty-1284p/bootloaders/optiboot/optiboot_atmega1284p.hex -v -v
but i have this result
avrdude: Version 5.10, compiled on Jun 29 2010 at 03:44:14
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2009 Joerg Wunsch
System wide configuration file is "/etc/avrdude.conf"
User configuration file is "/home/marco/.avrduderc"
Using Port : /dev/ttySA0
Using Programmer : avrispv2
AVR Part : ATMEGA1284P
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PA0
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
eeprom 65 10 128 0 no 4096 8 0 9000 9000 0xff 0xff
flash 65 10 256 0 yes 131072 256 512 4500 4500 0xff 0xff
lock 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
lfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
efuse 0 0 0 0 no 1 0 0 9000 9000 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
Programmer Type : STK500V2
Description : Atmel AVR ISP V2
Programmer Model: STK500
Hardware Version: 15
Firmware Version Master : 2.10
Topcard : Unknown
Vtarget : 0.0 V
SCK period : 0.1 us
Varef : 0.0 V
Oscillator : 3.686 MHz
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e9706
avrdude: erasing chip
"Ulock" memory type not defined for part "ATMEGA1284P"
avrdude: safemode: Fuses OK
avrdude done. Thank you.
i have a 1284-pu and not 1284p-pu but i have change signature in my .avrduderc file
thanks
Marco