I also believe the ones I received were fake.  I ordered the oiled leather in habana.  The buckles and sole did match pictures from birkenstock's website.  But, they felt strange.  They seemed too big for the size and the arch seemed too high and in the wrong spot.  I went to a local seller that is actually authorized on birkenstock's website to compare.  They did not have the same sandals in the same size, but a different sandal in the same size did feel different in the arch.  I returned these amazon ones and am waiting for ones I ordered from birkenstock's own web site.