Okay, this is a good guitar, just got it today. Okay, I'm noticing some weird buzzing coming from the 6th string, E. It almost sounds like there is something in the guitar when I hit the 7th or ninth fret.

Is this an abnormal problem, or should I get new strings, take it back, or describe the problem further?
You might need to setup the guitar to get rid of the buzz. Further details would probably be helpful.
- When I was your age Pluto was still a Planet. - anonymous
Setup? What does that mean?

Anyway, it seems to get better as I play it, but there is still a slight rattling sound on the 6th string.
it should go after a while.. may just be the strings, then again, the neck might be a bit out of whack. but whatever you do, DO NOT try to fix that on an acoustic, unless you know what you're doing.
Yeah, I'm sorry, keep playing it for a while before you consider a setup. When the buzz is still there take it to the next guitar shop and have them adjust your trustrod. It'll probably take them about 5 minutes and you can have them explain it to you. Next time, you're set to do it on your own.
- When I was your age Pluto was still a Planet. - anonymous
Set up is when you adjust something on your guitar. For example, adjusting the truss rod or changing your bridge height. I have the same guitar and have never had problems with it buzzing. Probably just a few turns of the truss rod would fix it. If your not comfortable doing that yourself you should take it to the store and have them do it... You could also do the buzz diagnostic here http://www.frets.com/FRETSPages/Luthier/Technique/Setup/BuzzDiagnosis/buzzintro.html