Off to bed...Disaster averted!

Well after spending a few hours debugging, looks like U4 in the Google Files group had a PDF with the chip backwards  As a result it was a bit cooked by the time I found it.  After thinking the whole I2C bus was bad, I realized I missed a jumper on the SoftRock 6.3 RXTX board.  I now have the temperature sensor functioning correctly as well as I2C querying of the SI570 :)  I'll update tomorrow with latest pics and info of the board and the modified SoftRock 6.3 RXTX board.  Definitely a fun project, and can't wait to get receive working!