From: Melbourne, Australia
I recieved the latest version of ISA 2006 in the action pack, and thought I would dogfood it myself before selling it to clients.
This is my setup: internet --> ISA2006 Server(Win2003 SP1) --> SBS 2003 Server(Win2003 SP1, Exch SP2)
So far I have been able to get OWA to work by telling the exchange server to not use its forms based authentication(unticked the http FBA option in Exchange manager) now ISA is using its forms to authenticate to the OWA site on exchange.
Make sure you install the SBS box in single NIC configuration and remove all the Windows firewall components on the SBS box. The ISA Firewall is now the firewall and SBS is just normal service, without the horrible networking breakages the SBS did to it.