Outlook 2007 Out of Office

[Sackboy]

Hi

I have a couple of issues with outlook 2007 clients connecting to an
Exchange 2007 server.

i either get a certificate error on opening up outlook, or i get an error
when trying to set the OOO up - saying that the exchange server is
unavailable, when it is very much available.

any ideas if the certificate error can be disabled in outlook? or how to get
outlook to set the OOO ok - it works fine using OWA and Outlook 2003 clients

thanks