Assuming you can actually get enough movement on the dr to do the job (and I've found you can't assume this), the problem probably lies in your cables - is there any friction in there?
For example, I was having a terrible time with the shifting on the Jamis. I knew the cable outers were a little long but didn't think much of it. Eventually I cut them back to the right length and all my shifting problems went away.
Are the outers new? Could be something in there.
I'm guessing that the bar ends are putting a tight curve in the cable somewhere and it's this that's causing the problem ... and my experience above suggests that you may be underestimating the effect so I suggest that you revisit the layout and be hyper critical of everything.
Either that or just squirt some light oil down the outers and see what happens. I know you aren't supposed to lubricate modern cables but I've come across too many experienced mechanics that privately advise you to do it.
Of course, if you got rid of the derailleurs and converted her to a fixed gear bike, you wouldn't have these problems
Richard