Stone-Cech extensions of probability measure spaces

It is proved that $P(\beta X)=\beta P(X)$ if and only if $P(X)$ is a pseudocompact space, where $P(X)$ is the space of probability Radon measures with weak topology and $\beta X$ is a Stone-Cech extension of the space $X$. A locally compact pseudocompact space $X$ is constructed such that $P(X)$ is not pseudocompact. Conditions are obtained under which $P(X)$ is pseudocompact.