I'm not sure about pinch flats, but I did have one flat by an area of the tube that showed all sorts of strange wear. What might be related is that I had a flat problem from debris getting into the tire. I went through 2 tubes (not including the one above) until I brought it up at the co-op, and they told me to clean out the inside of the tire. Is it common to get junk inside the tire?
700 x 35c Kenda K-830 are the tires it came with, and I've been buying 700 x 28 - 32 tubes I believe in all cases.
I'd love to go out and buy some velocity deep v's and nice tires, but it just isnt in the budget, so makeshift workarounds and maintenance seem are the route for the time being.