Well, some suggestions and thoughts.
1.) In kernel 3.8, I think I2C Pins P9.19 and P9.20 report as I2C-1, so you should see the part on that bus.
2.) Make sure you have not swapped the SCL and SDA lines. Make sure that you are really connected to P9.19 and P9.20.
You should see activity on both lines with an oscilloscope when you are running an I2C probe. Make sure that you have
pull-up resistors on each line, so that the lines go high when idle
3.) If you have another I2C part, like an EEPROM memory chip, or an I/O Expander, wire that onto the bus and see if it works.
4.) Try a later version of Debian with the 4.1 kernel. 2015-06-19 or 2015-06-29. These have the latest cape manager installed,