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 ISA Server and service pack; whether ISA is a Proxy only or proxy/firewall installation; is the ISA FWC 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 ISA/Forefront Service Packs and updates and retested prior to asking the question.........
Keith Alabaster
Moderator