IIS certificate problem

Hello,

We have a Win2003R2sp2 server with one MOSS web application and a shared
services site. This have their own subdomains (site1.domain.com &
site2.domain.com) which point to separate ip addresses (let's just say IP1 &
IP2).

Both sites use SSL, and we have installed certificates for both IIS sites.
Certificates are from a trusted CA, one for site1.domain.com and other for
site2.domain.com. There should be no need for wildcard certificates, as both
sites have unique ip addresses. So the first site responds to IP1:443 and
second site to IP2:443 (the same can be seen in SecureBindings value with
SSLDiag).

Now, the browsing the sites works fine. But the site2 the browser gets the
certificate for site1.domain.com and correctly complains about a certificate
error.

Why does site2 offer the certificate of site1, although the IIS shows that
the right certicicate is installed? Should I modify SSL headers with the
command line, even though I have two ip addresses?