Thanks for your very informative playground article
Would you mind checking your onboard regulator output, mine is 4.3V with 5V or 3.3V supply
I'm glad my sketch did help.
I have a good multimeter. My +5V is 4.95V and the 3.3V of the breakout board is 3.31V.
Also the XDA and XCL of the sub-I2C-bus pins are 3.31V (I think they have a pull-up somewhere).
My MPU-6050 is connected to the I2C via a level shifter, so I have not current flow from the I2C to the MPU-6050 voltage.
Can you measure the SDA and SCL (while not active), and check the XDA and XCL ?
Your breakout board has 10k pull-up resistors to the 3.3V.
That should be 4k7 to be safe.
I think that it might perhaps cause the higher voltage.
Can you add another two pull-up resistors of 10k from the SDA and SCL to the 3.3V of the Arduino board ?
The 4k7 prevents that the internal pull-up resistors in the avr chip (on the Arduino board) raises the voltage of the I2C too high for 3.3V devices.
I have added your GY-52 breakout board : http://arduino.cc/playground/Main/MPU-6050