Huston... we have a problem.
I've changed the I2C address of my NXTCam to 0x04 and then... to 0x01 (internal to 0x00)... so I can not communicate to the NXTCam.
But I think if I could change the master I2C address of my Arduino... then I can connect to 0x00.
Is this possible?
Can you give a link to the NTXTCam ?
What does the I2C address of the Arduino has to do with it ? A Master has no address, although the Arduino can be a Master and also receive messages as a Slave as well.
Link: http://www.mindsensors.com/ev3-and-nxt/14-vision-subsystem-camera-for-nxt-or-ev3-nxtcam-v4
Documents: http://www.mindsensors.com/ev3-and-nxt/14-vision-subsystem-camera-for-nxt-or-ev3-nxtcam-v4
Don't know... but as I used I2C Address 0x00 to connect the NXTCam... first i got nothing, then after a while I got some bytes and then nothing. So I thing the Cam has 0x00 ... but with 0x00 it's not working fine as it was with 0x01/0x02
Over USB the NXTCam is working fine... but I can use it with I2C and Arduino only, so I need I2C.
Normally it should be possible to flash the NXTCam Firmware with an USB connection like Arduino... but the Mindsensors FIrmware Flash tool didn't find the Cam with connected USB cable (I can connect the Cam over USB with "Term" and sending commands... so it's not an USB or driver issue).
Maybe someone has a lucky information.
Try the i2c_scanner, and change the for loop to check address 0 and 127 as well.
http://playground.arduino.cc/Main/I2cScanner
for(address = 0; address <= 127; address++ )
Try it with the NXTCam connected and with nothing connected.
I2C address "0" is the broadcast address. Perhaps it is used in a different way in the Arduino hardware and software.
It is possible to use a software I2C, for example SoftwareWire, which does not have something special for address 0.
It might be easier to reflash the firmware. Is there a procedure to return to the factory settings ?
This I have tried yesterday always (I2C scanner), not working... other devices will be found.
It seems that the only way to flash a new firmware over I2C 
and thats not working 
... It' unbelievable thats so complicated ;-), it can't be more.
I think the $150 thing is trash now
Anyway... it was funny.