Just for the record, I had a similar problem setting up the i2c communication on wheezy just the other day. I ran across a website (http://www.skpang.co.uk/blog/archives/575
) that explained that on the new Raspbian distro, the i2c driver is installed but disabled. What you can do is just edit the file responsible using the following unix command:
sudo nano /etc/modprobe.d/raspi-blacklist.conf
Then comment out the i2c line (below) by putting a # in front (you can do the same for the spi line if you use that):
It worked fine for me.