Model problems

FP Mie

Hi I'm having some problems with my model of an airfoil in water, at 5 m/sec. My model had been working correctly, with good Cd and Cl figure, and good flow visualisation. If I take a case and data file, and start running it from where I left off, its fine. However, if I take in the same case and data file, and re-initialise the model, with all the same conditions and properties as before, it behaves badly-i.e. velocity jumps from 5m/sec to over 7000 m/sec, with the result that all pressure/velocity calculations are completely wrong. has anyone had this problem, or could anyone suggest a fix? Thanks FP