I am doing this by memory. I cannot pull up the links I have read. This is one link I did find that I am taking some info from. https://bitcointalk.org/index.php?topic=786544.0   - but I did read somewhere that bitcoins are linked with an "internet like link" and it is designed this way for the purpose of tracking.
And in this link http://bitcoin.stackexchange.com/questions/11580/how-untraceable-is-bitcoin on point 3 they say they are traceable, but may not be traceable directly back to me. But could be if enough work and effort is put in.
A few places I have read say the ip address IS directly connected to bitcoin transactions going very far back. One post I saw said that having a verifiable ip connected to any "chain of custody" of bit coin transactions can be and will be tracked back to any certain point in time if there is a need.

An example given to me in a private conversation from someone who has done what I am trying to do said that you should not allow an ip address to be connected to any bitcoin transaction and to run different bitcoin values through different mixers and wallets and he did mention using some bit coin to buy Darkcoin and then move it back to bitcoin varing the amount and times to make it as clean as possible.