Thanks for the tip. I may play with that a bit depending on what they tell me about bringing it in and how long it will take, etc.

I was playing with it some more today and what it seems to be doing is when I start on the largest rear gear and shift, nothing happens. Shift again and it drops 2 gears. Sometimes 1, but most times 2. Shift again and nothing happens. Shift again and it drops 2 gears. So, in a nutshell it seems to be shifting every other shift and dropping 2 gears at a time. When I start shifting from smaller to bigger, the first shift does nothing. Then every subsequent shift pretty much changes by the proper 1 gear. Does that still sound like something adjusting the cable might help? I'm pretty naive in bicycle mechanics, so I don't have a clue.