I'm trying to solve the following problem:

Minimize[{NProbability[(1 - 2 g)*y + g^.5 + s < 
x, {x, y} \[Distributed] UniformDistribution[{{0, 1}, {0, 1}}]], 0 < g < 1 && 0 < s < 1}, {g, s}]

This code gives an error message from NIntegrate (NIntegrate::izero)

Any ideas why the error message? If I run a contour plot of the objective over the constrained area I get something that looks well behaved...