I've run the Ventus V12's on my '99 Box on street, track and AX. My experience, with that model, is that they are very good street tires with softer sidewalls than the Sumis I currently have, the Bridgstones and Pirellis I've had before. I had to increase tire pressure by about 4-6 psi in both AX and track use to keep the tire from rolling over the indicators. You don't say if these are the V12's but you might try increasing the PSI to stiffen the sidewall the next time you go out and see if it makes a difference.
