I have discovered that SBS2008 (sometimes?) have problems with importing a wildcard cert to use as a trusted cert. I have not been able to confirm this since I only have one trusted wildcard cert, but I will try to confirm it and update this post. The cert was issued to *.mydomain.com as it should be as it is a wildcard cert, and my SBS server was configured to use remote.mydomain.com for RWW. When trying to run the “Add Trusted Certificate” wizard the system would not let me select my trusted cert from the Personal/Certificates store on the SBS Server. However it did present me with the remote.mydomain.com certificate. There was no chaining or permission errors on the certificate and it was exportable and all extenssions were also imported.
What I did was to go into the registry and change HKLM\SOFTWARE\Microsoft\SmallBusinessServer\Networking\PublicFQDNPrefix to * instead of remote. Then ran the wizard. It now presented me with the option to use the wildcard cert instead. Selected the wildcard and then finished the wizard. Changed the registry value back to remote and everything works fine.