Sounds to me like both shift cables need to be tweaked a bit--probably trimmable with the barrel adjusters.

There's an off chance that the barrel adjuster won't give enough adjustment--in that case you would have to adjust the length of the cable by loosening the bolt securing the end of the cable to the derailleur, adjusting the cable position slightly (eighth of an inch or so) in the desired direction, and re-tightening.

New cables and housings both tend to 'stretch' a little when first installed so adjusting after the first 50 miles or so is pretty common. You may have to tweak up the adjusters a few times, but things should settle down within a couple of hundred miles--at least until you replace the cables in a couple of years and start the cycle all over again.

The Park tool website (specifically the repair help section at http://parktool.com/blog/repair-help) is a great bike maintenance resource, by the way.

edit: linked the repair help page directly as it's difficult to find from the new, "improved" (i.e., not) layout.