Numerical instability with water vapor condensation in ECO2M

Hey everyone,

I've run into an issue trying to make the transition from a saturated gas to a 2-phase stream composed of a wetting aqueous phase and a gaseous CO2/H2O(g) mixture.  I don't see anything about addressing the g ==> a+g transition in the ECO2m manual, and I've attempted very low time steps (~10^-10 sec.) and refined meshes.  I've also attempted a rather large (10^-3) "finite window" for phase changes (SELEC.1 record IE(9) = 3, SELEC.2 record FE(3) = 10^-3, SELEC.2 record FE(4) = 10^-3).  Does anyone else have a suggestion as to what I should do?

Thanks!

- Mikey