If you could, please download a fresh copy of HS 1.5.1 and run it. In order for me to test and patch this, I need a common, reproducible test case.
We normally don't put out a notice until we're able to verify there is an issue. As with most things microsoft, you shouldn't run to update windows versions the moment it comes out. The last few releases have either been pulled or have caused performance related issues. When we verify that is an issue with an RC we will make a post related to it.