Only other factor that might be causing trouble that I can think of is this:
What are these two black washers for?The shifters have these two washers, with a tab that sticks out perpendicular to the washer face. I think it is not meant to go with the bar end pod, but the bike came this way. These are DT shifter mounted on bar end pods. Maybe trying it without the washers may help? I don't know what they are for.
