roland midi driver + due

Hello.
I've been playing for a while with arduino duemilanove and the "roland serial midi driver" to build a "midi drum" (yes another one) working as a midi controller connected directly to my pc via usb.
I picked the configuration steps in this forum (topic "Midi direct via USB") a couple of years ago, so i didn't need to load any additional program (s2midi,hairless,etc.) neither install virtual serial ports (loopbe,midiyoke,etc.), in other words it works like a charm with duemilanove.
Now i'm trying to go forward with a "Due" but i can't get it.
The sketch and the board are working fine when i use the serial monitor, but de roland driver doesn't work, i tried reinstalling but nothing. Apparently the problem is related to the disappeared "ftdi port", which i reinstalled too without success.
I read about a project to make arduino to act as a mid hid device (http://mitat.tuu.fi), but when i tried it sends error messages, i wrote to the author yet, but i wonder if any of you has solved this in a risky less way, cause as i understood i've got to load a hacked firmware but i'm afraid it would spoil the board.
I appreciate any help and thanks for reading.

OK, reading posts here and there i finally give up with ftdi, cause Due has none, end of the story ... but...
in other posts i found some information to use the Duemilanove as SPI to load the HIDuino firmware (or so a think) to the Due.
So i decided to try loading the original Due firmware to be sure what i'm doing,
i load the ArduinoISP sketch to the duemilanove, previous to connect the capacitor.
i wired both boards as shown here http://arduino.cc/en/Tutorial/ArduinoISP (except the 5v, where i use 3.3v indeed in both sides) and then i put a 10uf capacitor in the duemilanove between ground and reset.
i have connected the duemilanove to the pc.
but when i run avrdude i get this message:

avrdude -C ..\etc\avrdude.conf -c arduino -P com1 -b19200 -p m16u2 -Uflash:w:usbserial_due_16u2.hex:i
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.03s
avrdude: Device signature = 0xffffff
avrdude: Yikes! Invalid device signature.
Double check connections and try again, or use -F to override
this check.
avrdude done. Thank you.

and when i add the -F switch i get the additional lines:

...
avrdude: Expected signature for ATmega16U2 is 1E 94 89
avrdude: NOTE: FLASH memory has been specified, an erase cycle will be performed
To disable this feature, specify the -D option.
avrdude: erasing chip
avrdude: reading input file "usbserial_due_16u2.hex"
avrdude: writing flash (4352 bytes):
Writing | ################################################## | 100% 5.50s
avrdude: 4352 bytes of flash written
avrdude: verifying flash memory against usbserial_due_16u2.hex:
avrdude: load data flash data from input file usbserial_due_16u2.hex:
avrdude: input file usbserial_due_16u2.hex contains 4352 bytes
avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 3.42s
avrdude: verifying ...
avrdude: verification error, first mismatch at byte 0x0000
0xa7 != 0xff
avrdude: verification error; content mismatch
avrdude: safemode: Fuses OK
avrdude done. Thank you.

i know i'm doing something wrong but can anyone tell me what is it ?

Thanks in advance.

ok, this is a monologue but maybe it could help someone...
i've found the right wiring here http://www.sainsmart.com/blog/due and finally i could load the hiduino firmware and it appears like a midi usb device and works fine, but as i understood it cannot interact with the IDE directly (i've tried but the IDE displays "No device found on com1"), and i must load the sketch before override the firmware, so my question now is, can i use the Duemilanove (as a SPI) to load sketches into the Due ?
Thank for reading.