I'm having a problem with getting the mavin sword from Erathsmedor...I didn't say elseramavin to him the first time I talked to him, and now he won't talk to me again. Is there anything I can do?

Have you "walked into him" and given him the Shroud? Then try Elseramavin again (you did get this magic word from the mouth of D'Soto's ghost and it was entered into your word pick list, right?).