Altus rear shifter problem -- lever doesn't return to neutral
So I've noticed in the past few rides that my rear shifter seems to have problems when I try to shift the rear gears towards the granny side. I push down on the lever and it'll go down all the way, but it won't go back up far enough. And it also seems to not be able to shift out of the granny and next gear over very easily.
It's the EZ Fire shifter on a 2007 bike... which has a mere 200 miles on it that I picked up a month or two ago.
Is this one of those new-cable-stretch things that will probably just go away if I take it back to the bike place and make 'em adjust it, or is it more likely that my shifter has suffered infant mortality and needs to be taken apart and/or replaced and probably means that I'm going to have to drive to work until they get it fixed up?