Two Windows Server 2008 SP1 boxes, both x64. One runs WCF service hosted in IIS secure website (SSL), the second consumes the service using WCF client.
The configuration does work just fine on two Windows Server 2008 SP1 x86.
Using IE we installed the certificate in all the possible storages on the client computer: IE navigation shows the services files without any certificate errors or warnings.
But the client won't work reporting
"The remote certificate is invalid accroding to the validation".
The problem is: using IE you install it into current user storage, not computer storage - thus the client running under its own service account still cannot validate the certificate.
We should install the certificate into computer storage using MMC and not the internet settings control panel applet.
Do not forget to launch the MMC as local admin!
Later seen also: