Dennis found an issue where even after applying ISA 2004 SP1 on top of Windows Server 2003 SP1, the RRAS service repeatedly restarted. He contacted PSS and found that there is another small issue causing this fault that can cause packets to drop and is caused by an MTU issue.
Symptoms are like:
Heres the resolution and it requires a hotfix: http://support.microsoft.com/?id=898060
I'm sure u are aware of this :)
V1.1 (May 11, 2005): Microsoft updated this bulletin today to advise customers that we plan to re-release the MS05-019 security update in June, 2005. Until the re-release of this security update is available, customers experiencing the symptoms described in Microsoft Knowledge Base Article 898060 should follow the documented instructions to address this issue. If you are not experiencing this network connectivity issue we recommend that you install the currently available security update to help protect against the vulnerabilities described in this security bulletin