General: inner tube failure

so, I replaced my back tire a week and a half ago or so, haven't had any problems. I'm pretty anal when mounting tires about making sure everything is seated properly. so... anyway I didn't ride for a couple days but I tend to check the pressure manually every day even if I'm not riding to make sure everything is kosher. yesterday it seemed fine, but today while I was making some front brake adjustments, I realized the back tire was flat! pumped it up to see what happened and heard a steady leak. took off the tire and the tube, marked on each the point where I could hear the hiss, and then inspected the tire itself for punctures. nothing. then pumped up the tube, found a steady small hole right next to the inner seam of the tube where the air was escaping. fearing burrs or something, examined the rim tape and spoke holes - the little hole was between spoke holes, and there were no burrs, etc. is this a defective tube? the LBS I bought it from is closed today so I'm thinking of bringing them the tube (riding another bike, obviously) and inflating it for them to see the small hole near the seam and explaining the problem. now, if the tube was defective, I do expect them to replace it, but I wanna make sure it doesn't happen again so - any ideas? there seem to be no burrs etc. but if replacing the rim tape will prevent this I'm willing to shell out a few bucks. tire was inflated to it's normal max psi (120). input? again, the hole was facing the rim, not above a spoke hole, and a mm or so away from the seam. I have a spare tube but wanted some advice before I remounted a tube in case it sounds like something other than a faulty tube. thanks yall.

if you can't find a problem, I'd patch the old tube and try reinstalling just in case your missing something and it pops it again.

from there either ride it if it's fine, or find or ask someone to help you find what's popping it. makee sure you line up your tires so you can see where it is on the innertube(label by the valve)

yup, checked the strip a few times, checked the inside of the tire (altho that was not where the [very small] puncture was), and, as per.k mentions, I line up the valve when installing tires for just that reason (and marked the point of puncture). it may have pinched but I've been riding it a week and a half at max pressure, shouldn't it have failed before now?

if it was a defective tube, in my experience the leak or tear would be along one of those seams. i had this problem with my back tire for a while and went through a few batches trying to find out what it was. every time it was a tiny cylinder shaped stretchy protrusion on the tube. it didn't get fixed until i changed the rimtape and to this day i have no clue what kept damaging the tubes.