By Mark Lamport-Stokes PACIFIC PALISADES, California (Reuters) - Moments after winning his ninth PGA Tour title at the Northern Trust Open on Sunday, Bubba Watson reflected on the work he still needs to do to improve his mental approach to the game. Earlier this month, Watson was left seething with frustration when negative comments he made about the venue for the Phoenix Open were twisted into criticism of the community there in Arizona, where he had previously lived. "I'm not over it," twice Masters champion Watson told reporters. More...