I also heard this to be true as of January, I am unsure if it has been lifted yet. I graduated in December and they started a freeze right after my class finished interviewing. As far as I knew it was only a freeze with new grads, so if you have experience there may be more positions available. I would try to contact the main Human Resource centers for both hospitals rather than just posting your resume on the websites. You will get more answers that way, at least in my experience.