On Conti tires (and most others) there is a ridge on the tire that sits a millimeter or two just above the rim when the tire is seated. When the tire is on and inflated, spin the wheel and watch to see that this ridge is concentric and pretty even from the rim, on both sides of the tire. If the tube is caught underneath the tire bead, you will be able to see a gross irregularity in the concentricity of this ridge.
-------------------- Steel lover, but then I like Ti with carbon too.
Licensed bike geek.