Need clarification regarding I2C and Bluetooth devices

Hi all,

I have BB XM-A3. I did two tests.

Test 1:

I have connected I2C based Memory and RTC - 24C04 and DS1307 with I2C -3. My external devices are +5V based. So I provided level converter which convert 1.8V signal to +5V signal. I had taken 1.8V from P13 connector and +5V from P11 connector. Also I had taken I2C-SDA and I2C-SCL signals from these two connectors. As soon as I connected my external PCB which has both 24C04 and DS1307 circuitry, I am not getting proper 1.8V on BB connector itself. It seems that 1.8V supply is getting overloaded. Also when I issued I2Cdetect -r 3 command, it was showing start signal timeout. Can anyone tell me how to come out from this problem ?

Test 2:

On same board, I had connected bluetooth dongle on USB port.when I issued df -h command, it is not showing bluetooth device.
Can anyone guide me how to connect bluetooth dongle on BB ?