Yes I had a problem with flats too. Turns out, using the old rubber spoke guard from another rim was a BAD idea, it moved around. But the big problem, I think was the 1 size fits all Walmart tube (no slime) which is too long for a 26" tire - I think they say for both 26" and 27". I ended up going to a tire shop (probably not somehting to admit) where they put on the CORRECT size innertube, and I noticed that they partially inflated it when installing as indicated above, also installed a new rim strip.
I like the idea of Kevlar tire, but would also rather have a balloon tire, which I have been unable to find at walmart. Go figure.