Before you ask your question, please take a bit of time to think about what it is you are looking to get help on. The more specific you are about what you are trying to achieve - and need help with, the easier it is for us to target the responses.
Tell us about the basic environment in which an error occurs or that you are working in. If you don't tell us then we will make assumptions and this can cause confusion.
Telling us the versions of Forefront Product being used and service packs deployed; whether this is a Proxy only or proxy/firewall installation; is the Firewall client deployed; each of these small bits of information allow respondees to focus on the issue
rather than having to make guesses or keep requesting further clarity.
Please be aware that the expectation will be that you have applied ALL operating system and Forefront Service Packs plus updates and retested prior to asking the question.........