I2C Interference? SD Logging Shield and BMP180 Not working together

I am working on a cave wind / barometer data logger. See post Cave wind / barometric pressure logging feasibility (FINISHED AND WORKING) - Project Guidance - Arduino Forum I have a clone adafruit data logging shield and a BMP180 that are interfering with one another. Each work on their own but trying to plug them in at the same time disconnects the arduino from the PCs serial port. Both are I2C. Do I have a pull up problem or something else? Worth getting a SPI Barometer?

I have solved this issue. I hooked the BMP180 up to 3.3v instead of the 5v pin. hmmm.