The poster of this question subsequently edited it and added a solution he had found. I left a comment asking him to post his edit as an answer instead (and self-accept if he feels like it), but he hasn't done so yet. Odd, because he's been a member of SO for over a year, and has self-answered before.
Anyway, suppose he never returns. In such cases it would be easy enough for any of us to move that solution to an answer, but is that the best way to go about it? In such situations can mods add answers as other users so the users get the credit? If not, should we add an answer and perhaps mark it as Community Wiki?