Do or do not... a contradiction?

Dog doo
Originally uploaded by ntt.

I was thinking about Star Wars today (as one often does), and I began to wonder if Yoda and Obi-Wan were contradicting each other with the following statements:

Yoda: "Do or do not, there is no try"

Obi-Wan: "Only Sith deal in absolutes"

Hmm... much to think upon, there is.