According to Danny Ainge in a recent interview, the Boston Celtics and the Blazers were "pretty close" to a trade back in 2005 which would have sent Paul Pierce to Portland in exchange for the #3 pick and salary cap ballast. We later traded the pick to Utah for #6 and some later picks, and took Martell.
Utah of course took DW with the pick; DW was the player that Ainge was eyeing instead.
The story didn't indicate why the trade fell through.
Back then, Pierce was coming off a season in which he did well statistically, but was blamed for the Celtics failure to advance in the playoffs, and had a few "Rasheed momemts" to boot--many thought that he would be sent packing from Boston.