(Clark Co., WA)  --  Authorities say a longtime Portland police officer who was off-duty was arrested in Clark County during the weekend for suspicion of DUI.  Officials say Rodney Gustafson has been with PPB for 27 years.  Authorities say Gustafson was arrested after he was spotted driving the wrong way on Highway 99 Saturday morning.  Sergeant Chuck Christensen of the Clark County Sheriff's Office tells "The Oregonian" a pair of sobriety tests returned blood-alcohol content readings of point-135 and point-137, respectively, compared to the legal limit of point-08.