The MLX90614 IR sensor communicates using SMBus which requires the Start bit be repeated without a stop bit in between. I saw one posting that looked like PBP that showed the I2CREAD as as working with the 90614.

sensortemp = 0
reg = $07
addr = 0
I2CRead Tda, Tcl, addr, reg, [sensortemp.lowbyte, sensortemp.highbyte]

where reg 7 is the location of the temperature data and addr 0 is the device address.

The I2CREAD command has Control and Address, so maybe Control == addr and Address == reg? What about the repeated Start bit?