Recently, I have acquired a Mandolin. I was having an easy enough time playing it (I also play the fiddle), but I have encountered a few problems.

1)   I am experiencing buzzing on the E string between the 4th through 6th frets

2)   On the E string, my 5th 6th frets are all playing B flat (the 7th fret)

I get the feeling these problems are related, but I have no idea what is causing it. I live in New Mexico, which has very low humidity, and I believe it was manufactured elsewhere in the States. When I purchased my Mandolin, it sounded just fine. I have tried to look on the internet for a clear answer, but have found none. If anyone could help me out or point me in the right direction, I would be grateful.

have you changed your strings recently?  you may need to if not.. it also sounds like you might need to adjust the action, and possibly adjust the bridge placement for intonation.. easy to follow instructions can be found over at www.frets.com for string changes and setup..
you might want to have a luthier do it for you (i did the first time) i think you should be able to find someone to do it for around $30
does your mando have an adjustable trussrod? i haven't messed with mine, but you use the truss rod to set the neck properly..

what kinda mando is it?  any pics?

Actually, looks like this problem has sort of solved itself. I asked a local bouzouki player to take a look at it, and he said that it was most likely a high fret that needed filing, or as you said, or have the action adjusted, like you said. So, I'll see what I can do about this. As for pictures, I have none off hand, and I'm unsure which model it is. However, it is manufactured by the Kentucky Mando (and guitar?) Company, and has F holes and is A style, and not round backed. The strings are unlikely to need changing, as the mando was fresh off the assembly line.

Thank you for the feedback, keith.

I have changed the action, and it's sounding fine.

good to hear!