Recently I had a string of flats that looked very suspicious. Turns out there were two holes close to the valve stem. Both holes were inline with the valve stem on either side of the valve roughly 3/4" away from the valve. I have ruled out the following causes: 1) Snakebite: Holes in this case would not be inline but rather on either side of the centerline of the tube. 2) Bad rimtape: No spoke nipples in the area. 3) Bad tube: Tried a few tubes, failure never at the seam or any other manufacturing relict. 4) Burr at the valve hole: The holes are too far away from the valve stem. Tube was a longstem tube. Rim a Mavic Ksyrium. Any idea what could be causing this? Tilman.