Responsibilities Of Editorial Page Editors

I'm throwing this question out for debate: what are the duties of newspaper editorial page editors when it comes to pointing out factual mistakes in Letters to the Editor? Do they have any moral responsiblities at all, as long as they have a statement that letters don't reflect their views, and they print later letters that point out the errors? Or should they put in an "Editor's Note" after clearly false claims stating that the writer is in error? What do you think?

I got thinking about this when reading the letters in yesterday's Idaho Statesman, and the top letter in this group made the "Barack Obama is a Muslim and went to a Wahabbi school" claim that's been thoroughly debunked. (Note: While I'm not supporting Sen. Obama for President under any conceivable circumstances, I do support the truth.)

Update 0827 13 June: I really appreciate Kevin Richert, the Idaho Statesman's Editorial Page editor, stopping by to offer his thoughts. (Truth be told, I appreciate all my commenters.) DFO from Huckleberries Online (on Spokane's Spokesman-Review website) opened up a parallel discussion over at his place, and offers his newpaper's policy on obvious LTTE errors:

We won't knowingly print a letter to the editor that contains false information. I've received calls from our letters editor asking me about claims made in Idaho letters. Occasionally, misinformation does slip through, however. Of course, many readers mistake opinion for fact. Also, we have kicked out letter writers who plagiarize other material.

I know the Statesman calls the writer of each LTTE to confirm that they actually submitted it. I'd like to see them at least inform the writers of obvious falsehoods that their letter contains a clear error, and ask them if they'd like to change it before they get flamed. Some people might actually not know that they have bad data; others, of course, are intentionally putting out disinformation for political or other reasons.